--- 1/draft-ietf-manet-dymo-11.txt 2008-02-07 08:12:09.000000000 +0100 +++ 2/draft-ietf-manet-dymo-12.txt 2008-02-07 08:12:09.000000000 +0100 @@ -1,19 +1,19 @@ Mobile Ad hoc Networks Working I. Chakeres Group Motorola Internet-Draft C. Perkins -Intended status: Standards Track Nokia -Expires: May 21, 2008 November 18, 2007 +Intended status: Standards Track +Expires: August 10, 2008 February 7, 2008 Dynamic MANET On-demand (DYMO) Routing - draft-ietf-manet-dymo-11 + draft-ietf-manet-dymo-12 Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that @@ -24,166 +24,171 @@ and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. - This Internet-Draft will expire on May 21, 2008. + This Internet-Draft will expire on August 10, 2008. Copyright Notice - Copyright (C) The IETF Trust (2007). + Copyright (C) The IETF Trust (2008). Abstract The Dynamic MANET On-demand (DYMO) routing protocol is intended for - use by mobile modes in wireless, multihop networks. It offers - adaptation to changing network topology and determines unicast routes - between DYMO routers within the network in an on-demand fashion. + use by mobile nodes in wireless, multihop networks. DYMO determines + unicast routes between DYMO routers within the network in an on- + demand fashion, offering improved convergence in dynamic topologies. Table of Contents 1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Applicability Statement . . . . . . . . . . . . . . . . . . . 4 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Data Structures . . . . . . . . . . . . . . . . . . . . . . . 7 4.1. Route Table Entry . . . . . . . . . . . . . . . . . . . . 7 4.2. DYMO Messages . . . . . . . . . . . . . . . . . . . . . . 8 - 4.2.1. Generalized MANET Packet and Message Structure . . . . 8 + 4.2.1. Generalized Packet and Message Structure . . . . . . . 8 4.2.2. Routing Messages (RM) - RREQ & RREP . . . . . . . . . 9 - 4.2.3. Route Error (RERR) . . . . . . . . . . . . . . . . . . 13 + 4.2.3. Route Error (RERR) . . . . . . . . . . . . . . . . . . 12 5. Detailed Operation . . . . . . . . . . . . . . . . . . . . . . 14 5.1. DYMO Sequence Numbers . . . . . . . . . . . . . . . . . . 14 5.1.1. Maintaining A Node's Own Sequence Number . . . . . . . 15 5.1.2. Numerical Operations on OwnSeqNum . . . . . . . . . . 15 5.1.3. OwnSeqNum Rollover . . . . . . . . . . . . . . . . . . 15 5.1.4. Actions After OwnSeqNum Loss . . . . . . . . . . . . . 15 5.2. DYMO Routing Table Operations . . . . . . . . . . . . . . 15 5.2.1. Judging Routing Information's Usefulness . . . . . . . 16 - 5.2.2. Creating or Updating a Route Table Entry with New - Routing Information . . . . . . . . . . . . . . . . . 17 + 5.2.2. Creating or Updating a Route Table Entry with + Received Superior Routing Information . . . . . . . . 17 5.2.3. Route Table Entry Timeouts . . . . . . . . . . . . . . 18 5.3. Routing Messages . . . . . . . . . . . . . . . . . . . . . 19 5.3.1. RREQ Creation . . . . . . . . . . . . . . . . . . . . 19 5.3.2. RREP Creation . . . . . . . . . . . . . . . . . . . . 20 - 5.3.3. Intermediate DYMO Router RREP Creation . . . . . . . . 21 + 5.3.3. Intermediate DYMO Router RREP Creation . . . . . . . . 20 5.3.4. RM Processing . . . . . . . . . . . . . . . . . . . . 21 5.3.5. Adding Additional Routing Information to a RM . . . . 24 5.4. Route Discovery . . . . . . . . . . . . . . . . . . . . . 24 5.5. Route Maintenance . . . . . . . . . . . . . . . . . . . . 25 5.5.1. Active Link Monitoring . . . . . . . . . . . . . . . . 26 5.5.2. Updating Route Lifetimes During Packet Forwarding . . 26 5.5.3. Route Error Generation . . . . . . . . . . . . . . . . 26 5.5.4. RERR Processing . . . . . . . . . . . . . . . . . . . 27 5.6. Unknown Message & TLV Types . . . . . . . . . . . . . . . 28 5.7. Advertising Network Addresses . . . . . . . . . . . . . . 28 - 5.8. Simple Internet Attachment and Gatewaying . . . . . . . . 28 + 5.8. Simple Internet Attachment . . . . . . . . . . . . . . . . 29 5.9. Multiple Interfaces . . . . . . . . . . . . . . . . . . . 30 - 5.10. Packet/Message Generation Limits . . . . . . . . . . . . . 30 - 6. Configuration Parameters and Other Administrative Options . . 30 - 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 31 + 5.10. DYMO Control Packet/Message Generation Limits . . . . . . 30 + 6. Configuration Parameters and Other Administrative Options . . 31 + 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 32 7.1. DYMO Message Type Specification . . . . . . . . . . . . . 32 7.2. Packet and Message TLV Type Specification . . . . . . . . 32 7.3. Address Block TLV Specification . . . . . . . . . . . . . 33 8. Security Considerations . . . . . . . . . . . . . . . . . . . 33 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 34 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 34 10.1. Normative References . . . . . . . . . . . . . . . . . . . 34 10.2. Informative References . . . . . . . . . . . . . . . . . . 34 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 35 Intellectual Property and Copyright Statements . . . . . . . . . . 36 1. Overview The Dynamic MANET On-demand (DYMO) routing protocol enables reactive, multihop unicast routing between participating DYMO routers. The basic operations of the DYMO protocol are route discovery and route - management. During route discovery, the originator's DYMO router - initiates dissemination of a Route Request (RREQ) throughout the - network to find a route to the target's DYMO router. During this - hop-by-hop dissemination process, each intermediate DYMO router - records a route to the originator. When the target's DYMO router - receives the RREQ, it responds with a Route Reply (RREP) sent hop-by- - hop toward the originator. Each intermediate DYMO router that - receives the RREP records a route to the target, and then the RREP is - unicast hop-by-hop toward the originator. When the originator's DYMO - router receives the RREP, routes have then been established between - the originating DYMO router and the target DYMO router in both + maintenance. + + During route discovery, the originator's DYMO router initiates + dissemination of a Route Request (RREQ) throughout the network to + find a route to the target's DYMO router. During this hop-by-hop + dissemination process, each intermediate DYMO router records a route + to the originator. When the target's DYMO router receives the RREQ, + it responds with a Route Reply (RREP) sent hop-by-hop toward the + originator. Each intermediate DYMO router that receives the RREP + creates a route to the target, and then the RREP is unicast hop-by- + hop toward the originator. When the originator's DYMO router + receives the RREP, routes have then been established between the + originating DYMO router and the target DYMO router in both directions. - In order to preserve routes in use, DYMO routers extend route - lifetimes upon successfully forwarding a packet. In order to react - to changes in the network topology, DYMO routers monitor links over - which traffic is moving. When a data packet is received for - forwarding if a route for the destination is not known or the route - is broken, then the DYMO router of source of the packet is notified. - A Route Error (RERR) is sent toward the packet source to indicate the - current route to a particular destination is broken. When the - source's DYMO router receives the RERR, it deletes the route. If the - DYMO router later receives a packet for forwarding to the same - destination, it must perform route discovery again. + Route maintenance consists of two operations. In order to preserve + routes in use, DYMO routers extend route lifetimes upon successfully + forwarding a packet. In order to react to changes in the network + topology, DYMO routers monitor links over which traffic is flowing. + When a data packet is received for forwarding and a route for the + destination is not known or the route is broken, then the DYMO router + of source of the packet is notified. A Route Error (RERR) is sent + toward the packet source to indicate the current route to a + particular destination is invalid or missing. When the source's DYMO + router receives the RERR, it deletes the route. If the source's DYMO + router later receives a packet for forwarding to the same + destination, it will need to perform route discovery again for that + destination. DYMO uses sequence numbers to ensure loop freedom [Perkins99]. Sequence numbers enable DYMO routers to determine the order of DYMO route discovery messages, thereby avoiding use of stale routing information. 2. Applicability Statement The DYMO routing protocol is designed for stub or disconnected mobile - ad hoc networks. DYMO handles a wide variety of mobility patterns by - dynamically determining routes on-demand. DYMO also handles a wide - variety of traffic patterns. In large networks DYMO is best suited - for traffic scenarios where nodes communicate with only a portion of - the other nodes. + ad hoc networks (MANETs). DYMO handles a wide variety of mobility + patterns by dynamically determining routes on-demand. DYMO also + handles a wide variety of traffic patterns. In networks with a large + number of routers, DYMO is best suited for sparse traffic scenarios + where routers forward packets to with only a small portion of the + other DYMO routers, due to the reactive nature of route discovery and + route maintenance. - DYMO is applicable to memory constrained devices, since little - routing state must be maintained in each DYMO router. Only routing - information related to active sources and destinations must be - maintained, in contrast to other routing protocols that require + DYMO is applicable to memory constrained devices, since minimal + routing state is maintained in each DYMO router. Only routing + information related to active sources and destinations is maintained, + in contrast to other more proactive routing protocols that require routing information to all routers within the routing region be maintained. DYMO supports routers which have multiple interfaces participating in - the MANET. DYMO also supports nodes which have non-MANET interfaces - to which hosts can attach. + the MANET. DYMO routers can also perform routing on behalf of other + nodes, attached via participating or non-participating interfaces. DYMO routers perform route discovery to find a route to a particular - destination. Therefore, DYMO routers must be configured to initiate - route discovery for certain destinations. When DYMO is the only - protocol interacting with the forwarding table, DYMO should be - configured to perform route discovery for all unknown unicast - destinations. + destination. Therefore, DYMO routers MUST be configured to initiate + route discovery on behalf of certain sources and find routes to + certain destinations. When DYMO is the only protocol interacting + with the forwarding table, DYMO MAY be configured to perform route + discovery for all unknown unicast destinations. - DYMO should only utilizes bidirectional links. In the case of - possible unidirectional links, either blacklists (see Section 7.2) or - other means (e.g. only accepting RM from bidirectional links as - indicated by NHDP [I-D.ietf-manet-nhdp]) of ensuring bi- - directionality should be used. Otherwise, persistent packet loss may - occur. + DYMO MUST only utilizes bidirectional links. In the case of possible + unidirectional links, either blacklists (see Section 7.2) or other + means (e.g. only accepting RM from bidirectional links as indicated + by NHDP [I-D.ietf-manet-nhdp]) of ensuring bi-directionality should + be used. Otherwise, persistent packet loss may occur. The routing algorithm in DYMO may be operated at layers other than - the network layer, using layer-appropriate addresses. Only - modification of the packet format is required. The routing algorithm - need not change. Note that, using the DYMO algorithm with message - formats other than those specified in this document will not be - interoperable. + the network layer, using layer-appropriate addresses. For operation + at other layers only modification of the packet/message format should + be required; DYMO's routing algorithm need not change. Note that, + using DYMO;s routing algorithm with formats other than those + specified in this document MAY NOT be interoperable. 3. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this - document are to be interpreted as described in RFC 2119 [RFC2119]. + document are to be interpreted as described in [RFC2119]. Additionally, this document uses some terminology from [I-D.ietf-manet-packetbb]. This document defines the following terminology: Distance (Dist) A metric of the distance a message or piece of information has traversed. The minimum value of distance is the number of IP hops traversed. The maximum value is 65,535. @@ -194,31 +199,31 @@ order of routing information generated and ensure loop-free routes. Forwarding Route A route that is used to forward data packets. Forwarding routes are generally maintained in a forwarding information base (FIB) or the kernel forwarding/routing table. Originating Node (OrigNode) The originating node is the DYMO router that creates a DYMO - Message in an effort to disseminate some information. The - originating node is also referred to as a particular message's - originator. + control message in an effort to disseminate some routing + information. The originating node is also referred to as a + particular message's originator. Route Error (RERR) A RERR message is used indicate that a DYMO router does not have forwarding route to one or more particular addresses. Route Reply (RREP) A RREP message is used to disseminate routing information about - the RREP OrigNode to the RREP TargetNode and the DYMO routers + the RREP OrigNode, to the RREP TargetNode and the DYMO routers between them. Route Request (RREQ) A RREQ message is issued to discover a valid route to a particular destination address, called the RREQ TargetNode. When a DYMO router processes a RREQ, it learns routing information on how to reach the RREQ OrigNode. Target Node (TargetNode) The TargetNode is the ultimate destination of a message. @@ -242,49 +247,46 @@ The route table entry is a conceptual data structure. Implementations may use any internal representation that conforms to the semantics of a route as specified in this document. Conceptually, a route table entry has the following fields: Route.Address The IP (host or network) destination address of the node(s) associated with the routing table entry. + Route.Prefix + Indicates that the associated address is a network address, rather + than a host address. The value is the length of the netmask/ + prefix. + Route.SeqNum The DYMO SeqNum associated with this routing information. Route.NextHopAddress The IP address of the next DYMO router on the path toward the Route.Address. Route.NextHopInterface The interface used to send packets toward the Route.Address. Route.Broken A flag indicating whether this Route is broken. This flag is set if the next hop becomes unreachable or in response to processing a RERR (see Section 5.5.4). - The following fields are optional: + The following field is optional: Route.Dist A metric indicating the distance traversed before reaching the Route.Address node. - Route.Prefix - Indicates that the associated address is a network address, rather - than a host address. The value is the length of the netmask/ - prefix. If an address block does not have an associated - PREFIX_LENGTH TLV [I-D.ietf-manet-packetbb], the prefix may be - considered to have a prefix length equal to the address length in - bits. - Not including optional information may cause performance degradation, but it will not cause the protocol to operate incorrectly. In addition to a route table data structure, each route table entry may have several timers associated with the information. These timers/timeouts are discussed in Section 5.2.3. 4.2. DYMO Messages When describing DYMO protocol messages, it is necessary to refer to @@ -299,175 +301,175 @@ | IP header | IP. | | UDP header | UDP. | | packetbb message header | MsgHdr. | | packetbb message TLV | MsgTLV. | | packetbb address blocks | AddBlk. | | packetbb address block TLV | AddTLV. | +----------------------------+-------------------+ Table 1 -4.2.1. Generalized MANET Packet and Message Structure +4.2.1. Generalized Packet and Message Structure DYMO messages conform to the generalized packet and message format as described in [I-D.ietf-manet-packetbb]. Here is a brief description of the format. A packet is made up of messages. A message is made up of a message header, message TLV block, and zero or more address blocks. Each of the address blocks may also have an associated address TLV block. All DYMO messages specified in this document are sent using UDP to the destination port MANET [I-D.ietf-manet-iana]. Most DYMO messages are sent with the IP destination address set to - the link-local multicast address LL MANET ROUTERS unless otherwise - stated. Therefore, all DYMO routers SHOULD subscribe to LL MANET - ROUTERS for receiving control packets. + the link-local multicast address LL-MANET-ROUTERS + [I-D.ietf-manet-iana] unless otherwise stated. Therefore, all DYMO + routers SHOULD subscribe to LL-MANET-ROUTERS [I-D.ietf-manet-iana] + for receiving control packets. Unicast DYMO messages specified in this document are sent with the IP destination set to the Route.NextHopAddress of the route to the TargetNode. - The IPv4 TTL (IPv6 Hop Limit) field for DYMO messages is set to one - (1) for all messages specified in this document. + The IPv4 TTL (IPv6 Hop Limit) field for all packets containing DYMO + messages is set to 255. If a packet is received with a value other + than 255, it is discarded. This mechanism helps to ensures packets + have not passed through any intermediate routers, and it is known as + GTSM [RFC5082]. The length of an IP address (32 bits for IPv4 and 128 bits for IPv6) inside a DYMO message depends on the IP packet header containing the DYMO message/packet. For example, if the IP header uses IPv6 - addresses then all messages and addresses contained in the payload - use IPv6 addresses. In the case of mixed IPv6 and IPv4 addresses, - please see [I-D.ietf-manet-packetbb]. + addresses then all addresses contained in the payload use IPv6 + addresses of the same length. In the case of mixed IPv6 and IPv4 + addresses, please use the methods specified in + [I-D.ietf-manet-packetbb]. If a packet contains only a single DYMO message and no packet TLVs, it need not include a packet-header [I-D.ietf-manet-packetbb]. The aggregation of multiple messages into a packet is not specified in this document, but the IP.SourceAddress and IP.DestinationAddress - of all contained messages must be the same. + of all contained messages MUST be the same. - Implementations may choose to temporarily delay transmission of + Implementations MAY choose to temporarily delay transmission of messages for the purpose of aggregation (into a single packet) or to improve performance by introducing jitter [I-D.ietf-manet-jitter]. + DYMO control packets SHOULD be given priority queue and channel + access. + 4.2.2. Routing Messages (RM) - RREQ & RREP Routing Messages (RMs) are used to disseminate routing information. There are two DYMO message types that are considered to be routing messages (RMs): RREQ and RREP. They contain very similar information and function, but have slightly different processing rules. The main difference between the two messages is that RREQ messages generally solicit a RREP, whereas a RREP is the response to RREQ. RM creation and processing are described in Section 5.3. A RM requires the following information: IP.SourceAddress The IP address of the node currently sending this packet. This field is generally filled automatically by the operating system and should not require special handling. IP.DestinationAddress The IP address of the packet destination. For RREQ the - IP.DestinationAddress is set to LL MANET ROUTERS. For RREP the - IP.DestinationAddress is set to the NextHopAddress toward the RREP - TargetNode. + IP.DestinationAddress is set to LL-MANET ROUTERS + [I-D.ietf-manet-iana]. For RREP the IP.DestinationAddress is set + to the NextHopAddress toward the RREP TargetNode. UDP.DestinationPort - The UDP destination port is set to MANET [I-D.ietf-manet-iana]. + By default, the UDP destination port is set to MANET + [I-D.ietf-manet-iana]. MsgHdr.HopLimit The remaining number of hops this message is allowed to traverse. AddBlk.TargetNode.Address The IP address of the message TargetNode. In a RREQ the TargetNode is the destination for which a forwarding route does not exist and route discovery is being performed. In a RREP the TargetNode is the RREQ OrigNode DYMO router. The TargetNode address is the first address in a routing message. AddBlk.OrigNode.Address - The IP address of the originator. In a RREQ the OrigNode is the - source's DYMO router for which a route discovery is being - performed. In a RREP the OrigNode is the RREQ TargetNode's DYMO - router for which a RREP is being generated. This address is the - second address in the message for RREQ. + The IP address of the originator and its associated prefix length. + In a RREQ the OrigNode is the source's DYMO router for which a + route discovery is being performed. In a RREP the OrigNode is the + RREQ TargetNode's DYMO router for which a RREP is being generated. + This address is the second address in the message for RREQ. OrigNode.AddTLV.SeqNum The DYMO sequence number of the originator's DYMO router. A RM may optionally include the following information: TargetNode.AddTLV.SeqNum The last known DYMO sequence number of the TargetNode. TargetNode.AddTLV.Dist The last known distance to the TargetNode. AddBlk.AdditionalNode.Address The IP address of an additional node that can be reached via the DYMO router adding this information. Each AdditionalNode.Address - must have an associated Node.SeqNum in the address TLV block. + MUST include its prefix length. Each AdditionalNode.Address MUST + also have an associated Node.SeqNum in the address TLV block. AdditionalNode.AddTLV.SeqNum The DYMO sequence number associated with this routing information. OrigNode.AddTLV.Dist A metric of the distance to reach the associated OrigNode.Address. This field is incremented by at least one at each intermediate DYMO router. AdditionalNode.AddTLV.Dist A metric of the distance to reach the associated AdditionalNode.Address. This field is incremented by at least one at each intermediate DYMO router. - OrigNode.AddTLV.Prefix - The OrigNode.Address is a network address with a particular prefix - length. - - AdditionalNode.AddTLV.Prefix - The AdditionalNode.Address is a network address with a particular - prefix length. - Example IPv4 RREQ 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 - IP Header +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IP.SourceAddress | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | IP.DestinationAddress = LL MANET ROUTERS | + | IP.DestinationAddress = LL-MANET-ROUTERS | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - ... + | IP TTL/HopLimit = 255 | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ UDP Header +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Destination Port = MANET | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - ... Message Header +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | RREQ-type | Rsv |N|1|1|0|1| msg-size=23 | + | RREQ-type |R|C|N|1|1|0|1|0| msg-size=23 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | msg-hoplimit | +-+-+-+-+-+-+-+-+ - ... - Message Body - Message TLV Block + Message TLV Block +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | msg-tlv-block-size=0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Message Body - Address Block +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - |Number Addrs=2 | Resv |0|1|0| HeadLength=3 | Head : + |Number Addrs=2 | Rsv |0|0|0|1|0| HeadLength=3 | Head : +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ : Head (cont) | Target.Tail | Orig.Tail | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Message Body - Address Block TLV Block +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | tlv-block-size=6 |DYMOSeqNum-type|Rsv|0|1|0|0|0|0| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Index-start=1 | tlv-length=2 | Orig.SeqNum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ @@ -481,31 +483,32 @@ RERR creation and processing are described in Section 5.5. A RERR requires the following information: IP.SourceAddress The IP address of the node currently sending this packet. This field is generally filled automatically by the operating system and should not require special handling. IP.DestinationAddress - The IP address is set to LL MANET ROUTERS. + The IP address is set to LL-MANET-ROUTERS [I-D.ietf-manet-iana]. UDP.DestinationPort - The UDP destination port is set to MANET [I-D.ietf-manet-iana]. + By default, the UDP destination port is set to MANET + [I-D.ietf-manet-iana]. MsgHdr.HopLimit The remaining number of hops this message is allowed to traverse. AddBlk.UnreachableNode.Address - The IP address of an UnreachableNode. Multiple unreachable - addresses may be included in a RERR. + The IP address of an UnreachableNode and its associated prefix + length. Multiple unreachable addresses may be included in a RERR. A Route Error may optionally include the following information: UnreachableNode.AddTLV.SeqNum The last known DYMO sequence number of the unreachable node. If a SeqNum for an address is not included, it is assumed to be unknown. This case occurs when a node receives a message to forward to a destination for which it does not have any information in its routing table. @@ -506,47 +509,50 @@ The last known DYMO sequence number of the unreachable node. If a SeqNum for an address is not included, it is assumed to be unknown. This case occurs when a node receives a message to forward to a destination for which it does not have any information in its routing table. Example IPv4 RERR 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 - IP Header +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IP.SourceAddress | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | IP.DestinationAddress = LL MANET ROUTERS | + | IP.DestinationAddress = LL-MANET-ROUTERS | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - ... - + | IP.TTL/HopLimit = 255 | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ UDP Header +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Destination Port = MANET | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - ... Message Header +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | RERR-type |Resv |0|1|1|0|1| msg-size=15 | + | RERR-type |R|C|N|1|1|0|1|0| msg-size=15 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | msg-hoplimit | +-+-+-+-+-+-+-+-+ - ... - Message Body - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | msg-tlv-block-size=0 |Number Addrs=1 | Resv |0|1|1| + Message TLV Block + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | msg-tlv-block-size=0 | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + Message Body - Address Block + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + |Number Addrs=1 | Rsv |0|0|0|1|1| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Unreachable.Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + Message Body - Address Block TLV Block + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TLV-blk-size=0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2 5. Detailed Operation 5.1. DYMO Sequence Numbers DYMO sequence numbers allow nodes to judge the freshness of routing @@ -558,48 +564,47 @@ own DYMO sequence number (OwnSeqNum), a 16-bit unsigned integer. The circumstances for ThisNode to incrementing its OwnSeqNum are described in Section 5.3. 5.1.2. Numerical Operations on OwnSeqNum When ThisNode increments its OwnSeqNum (as described in Section 5.3) it MUST do so by treating the sequence number value as an unsigned number. - Note: The sequence number zero (0) is reserved. - 5.1.3. OwnSeqNum Rollover If the sequence number has been assigned to be the largest possible number representable as a 16-bit unsigned integer (i.e., 65,535), then the sequence number is set to 256 when incremented. Setting the sequence number to 256 allows other nodes to detect that the number has rolled over and the node has not lost its sequence number. 5.1.4. Actions After OwnSeqNum Loss - A node should maintain its sequence number in persistent storage, - between reboots. + A DYMO router SHOULD maintain its sequence number in persistent + storage. - If a node's OwnSeqNum is lost, it must take certain actions to avoid - creating routing loops. To prevent this possibility after OwnSeqNum - loss a node MUST wait for at least ROUTE_DELETE_TIMEOUT before fully - participating in the DYMO routing protocol. If a DYMO control - message is received during this waiting period, the node SHOULD - process it normally but MUST NOT transmit or retransmit any DYMO - messages. If a data packet is received for forwarding to another - destination during this waiting period, the node MUST generate a RERR - message indicating that this route is not available and reset its - waiting timeout. At the end of the waiting period a node sets its - OwnSeqNum to one (1). + If a DYMO router's OwnSeqNum is lost, it MUST take certain actions to + avoid creating routing loops. To prevent this possibility after + OwnSeqNum loss a DYMO router MUST wait for at least + ROUTE_DELETE_TIMEOUT before fully participating in the DYMO routing + protocol. If a DYMO control message is received during this waiting + period, the DYMO router SHOULD process it normally but MUST NOT + transmit or retransmit any DYMO messages. If a data packet is + received for forwarding to another destination during this waiting + period, the DYMO router MUST generate a RERR message indicating that + this route is not available and reset its waiting timeout. At the + end of the waiting period the DYMO router sets its OwnSeqNum to one + (1) and begins participating. - The longest a node must wait is ROUTE_AGE_MAX_TIMEOUT. At the end of + The longest a node need wait is ROUTE_AGE_MAX_TIMEOUT. At the end of the maximum waiting period a node sets its OwnSeqNum to one (1) and begins participating. 5.2. DYMO Routing Table Operations 5.2.1. Judging Routing Information's Usefulness Given a route table entry (Route.SeqNum, Route.Dist, and Route.Broken) and new incoming routing information for a particular node in a RM (Node.SeqNum, Node.Dist, and RM message type - RREQ/ @@ -607,24 +612,25 @@ determine its usefulness. Incoming routing information is classified as follows: 1. Stale If Node.SeqNum - Route.SeqNum < 0 (using signed 16-bit arithmetic) the incoming information is stale. Using stale routing information is not allowed, since doing so might result in routing loops. (Node.SeqNum - Route.SeqNum < 0) + using 16-bit arithmetic 2. Loop-possible If Node.SeqNum == Route.SeqNum the incoming information may cause - loops if used; in this case additional information must be + loops if used; in this case additional information MUST be examined. If Route.Dist or Node.Dist is unknown or zero (0), then the routing information is loop-possible. If Node.Dist > Route.Dist + 1, then the routing information is loop-possible. Using loop-possible routing information is not allowed, otherwise routing loops may be formed. (Node.SeqNum == Route.SeqNum) AND ((Node.Dist is unknown) OR (Route.Dist is unknown) OR (Node.Dist > Route.Dist + 1)) @@ -648,201 +654,184 @@ - Route.SeqNum > 0 (using 16-bit signed arithmetic). In the case of equal sequence numbers, the information is superior in multiple cases: (case i) if Node.Dist < Route.Dist; (case ii) if Node.Dist == Route.Dist + 1 AND Route.Broken == true (a broken route is being repaired); (case iii) if Node.Dist == Route.Dist AND it is a RREP (RREP with equal distance are forwarded) OR Route.Broken == true (a broken route is being repaired). For completeness, we provide the following (optimized) pseudo-code. (Node.SeqNum - Route.SeqNum > 0) OR + using 16-bit arithmetic ((Node.SeqNum == Route.SeqNum) AND ((Node.Dist < Route.Dist) OR ((Node.Dist == Route.Dist + 1) AND (Route.Broken == true)) OR ((Node.Dist == Route.Dist) AND ((RM is RREP) OR (Route.Broken == true))))) -5.2.2. Creating or Updating a Route Table Entry with New Routing - Information +5.2.2. Creating or Updating a Route Table Entry with Received Superior + Routing Information The route table entry is populated with the following information: 1. the Route.Address is set to Node.Address, - 2. the Route.SeqNum is set to the Node.SeqNum, + 2. the Route.Prefix is set to the Node.Prefix. - 3. the Route.NextHopAddress is set to the node that transmitted this + 3. the Route.SeqNum is set to the Node.SeqNum, + + 4. the Route.NextHopAddress is set to the node that transmitted this DYMO RM packet (i.e., the IP.SourceAddress), - 4. the Route.NextHopInterface is set to the interface that this DYMO + 5. the Route.NextHopInterface is set to the interface that this DYMO packet was received on, - 5. if known, the Route.Dist is set to the Node.Dist, - - 6. if known, the Route.Prefix is set to the Node.Prefix. + 6. if known, the Route.Dist is set to the Node.Dist, Fields without known values are not populated with any value. Previous timers for this route table entry are removed. A timer for the minimum delete timeout (ROUTE_AGE_MIN) is set to - ROUTE_AGE_MIN_TIMEOUT. A timer to indicate a recently learned route - (ROUTE_NEW) is set to ROUTE_NEW_TIMEOUT. A timer for the maximum - delete timeout (ROUTE_AGE_MAX). ROUTE_AGE_MAX is set to - Node.AddTLV.MaxAge if included; otherwise, ROUTE_AGE_MAX is set to - ROUTE_AGE_MAX_TIMEOUT. The usage of these timers and others are + ROUTE_AGE_MIN_TIMEOUT. A timer for the maximum delete timeout + (ROUTE_AGE_MAX). ROUTE_AGE_MAX is set to Node.AddTLV.VALIDITY_TIME + [I-D.ietf-manet-timetlv] if included; otherwise, ROUTE_AGE_MAX is set + to ROUTE_AGE_MAX_TIMEOUT. The usage of these timers and others are described in Section 5.2.3. - At this point, a forwarding route should be installed. Afterward, - the route can be used to send any queued data packets and forward any + At this point, a forwarding route should be created. Afterward, the + route can be used to send any queued data packets and forward any incoming data packets for Route.Address. This route also fulfills any outstanding route discovery attempts for Node.Address. 5.2.3. Route Table Entry Timeouts 5.2.3.1. Minimum Delete Timeout (ROUTE_AGE_MIN) When a DYMO router transmits a RM, other DYMO routers expect the transmitting DYMO router to have a forwarding route to the RM originator. After updating a route table entry, it should be maintained for at least ROUTE_AGE_MIN. Failure to maintain the information might result in lost messages/packets, or in the worst case scenario several duplicate messages. After the ROUTE_AGE_MIN timeout a route can safely be deleted. 5.2.3.2. Maximum Delete Timeout (ROUTE_AGE_MAX) - Sequence number information is time sensitive, and must be deleted - after a time in order to avoid conflicts due to reboots and - rollovers. When a DYMO router has lost its sequence number (e.g, due - to daemon reboot or node replacement) the DYMO router must wait until - routing information associated with that IP address and sequence - number are no longer maintained by other DYMO routers in the network - to ensure loop-free routing. + Sequence number information is time sensitive, and MUST be deleted + after a time in order to ensure loop-free routing. - After the ROUTE_AGE_MAX timeout a route must be deleted. All + After the ROUTE_AGE_MAX timeout a route MUST be deleted. All information about the route is deleted upon ROUTE_AGE_MAX timeout. If a forwarding route exists it is also removed. -5.2.3.3. New Information Timeout (ROUTE_NEW) - - As time progresses the likelihood that a route remains intact - decreases, if the network nodes are mobile. Maintaining and using - old routing information can lead to many DYMO messages and excess - route discovery delay. - - After the ROUTE_NEW timeout if the route has not been used, a timer - for deleting the route (ROUTE_DELETE) is set to ROUTE_DELETE_TIMEOUT. - -5.2.3.4. Recently Used Timeout (ROUTE_USED) +5.2.3.3. Recently Used Timeout (ROUTE_USED) When a route is used to forward data packets, this timer is set to expire after ROUTE_USED_TIMEOUT. This operation is also discussed in Section 5.5.2. If a route has not been used recently, then a timer for ROUTE_DELETE is set to ROUTE_DELETE_TIMEOUT. -5.2.3.5. Delete Information Timeout (ROUTE_DELETE) +5.2.3.4. Delete Information Timeout (ROUTE_DELETE) As time progresses the likelihood that old routing information is useful decreases, especially if the network nodes are mobile. Therefore, old information should be deleted. After the ROUTE_DELETE timeout, the routing table entry should be deleted. If a forwarding route exists, it should also be removed. 5.3. Routing Messages 5.3.1. RREQ Creation When a DYMO router creates a RREQ it SHOULD increment its OwnSeqNum by one (1) according to the rules specified in Section 5.1.2. Incrementing OwnSeqNum will ensure that all nodes with existing - routing information to consider this new information fresh. If the - sequence number is not incremented, certain DYMO routers might not - consider this information useful if they have superior information - already. + routing information will consider this new information superior to + existing routing table information. If the sequence number is not + incremented, certain DYMO routers might not consider this information + superior, if they have existing better routing information already. First, ThisNode adds the AddBlk.TargetNode.Address to the RREQ; the - IP.DestinationAddress for which a forwarding route does not exist. + unicast IP Destination Address for which a forwarding route does not + exist. If a previous value of the TargetNode.SeqNum is known (from a routing table entry using longest-prefix matching), it SHOULD be placed in TargetNode.AddTLV.SeqNum in all but the last RREQ attempt. If a TargetNode.SeqNum is not included, it is assumed to be unknown by processing nodes. This operation ensures that no intermediate DYMO routers reply, and ensures that the TargetNode's DYMO router increments its sequence number. - Similarly, if a previous value of the TargetNode.Dist is known, it - SHOULD be placed in TargetNode.AddTLV.Dist. Otherwise, the - TargetNode.AddTLV.Dist is not included and assumed unknown by - processing nodes. - - Next, the node adds AddBlk.OrigNode.Address to the RM and the - OrigNode.AddTLV.SeqNum (OwnSeqNum) in an address block TLV. + Next, the node adds AddBlk.OrigNode.Address, its prefix, and the + OrigNode.AddTLV.SeqNum (OwnSeqNum) to the RM. The OrigNode.Address is the address of the DYMO router that is - initiating this route discovery. The OrigNode.Address must be a - routable IP address. If this DYMO router is performing route + initiating this route discovery. The OrigNode.Address MUST be a + unicast IP address. If this DYMO router is performing route discovery on behalf of an attached node (i.e. the source of the data packet causing this route discovery), the DYMO router MUST advertise - it's address and prefix that contain the source's address. This + an address and prefix that contain the source's address. This information will be used by nodes to create a route toward the - OrigNode, enable delivery of a RREP, and eventually for data packets. + OrigNode, enabling delivery of a RREP, and eventually used for proper + forwarding of data packets. If OrigNode.Dist is included it is set to a number greater than zero (0). - The MsgHdr.HopLimit should be set to MAX_HOPLIMIT, but may be set - smaller. + The MsgHdr.HopLimit SHOULD be set to MAX_HOPLIMIT. - For RREQ, the MsgHdr.HopLimit may be set in accordance with an + For RREQ, the MsgHdr.HopLimit MAY be set in accordance with an expanding ring search as described in [RFC3561] to limit the RREQ - propagation to a subset of the network and possibly reduce route - discovery overhead. + propagation to a subset of the local network and possibly reduce + route discovery overhead. - The IP.DestinationAddress for RREQ is set to LL MANET ROUTERS. + The IP.DestinationAddress for RREQ is set to LL-MANET-ROUTERS. 5.3.2. RREP Creation + First, the AddBlk.TargetNode.Address is added to the RREP. The + TargetNode is the ultimate destination of this RREP; the RREQ + OrigNode.Address. + + Next, AddBlk.OrigNode.Address and prefix is added to the RREP. The + AddBlk.OrigNode.Address MUST be a unicast IP address. If the RREQ + TargetNode is this DYMO router, its address is added to the RREP as + the OrigNode.Address. If the RREQ TargetNode is attached to this + DYMO router, ThisNode MUST advertise an address and prefix that + contain the RREQ TargetNode.Address. + When the TargetNode's DYMO router creates a RREP, if the - TargetNode.SeqNum was not included in the RREQ it MUST increment its - OwnSeqNum by one (1) according to the rules specified in - Section 5.1.2. + TargetNode.SeqNum was not included in the RREQ, ThisNode MUST + increment its OwnSeqNum by one (1) according to the rules specified + in Section 5.1.2. If TargetNode.SeqNum is included in the RM and TargetNode.SeqNum - OwnSeqNum < 0 (using signed 16-bit arithmetic), OwnSeqNum SHOULD be incremented by one (1) according to the rules specified in Section 5.1.2. If TargetNode.SeqNum is included in the RM and TargetNode.SeqNum == OwnSeqNum (using signed 16-bit arithmetic) and Dist will not be included in the RREP being generated, OwnSeqNum SHOULD be incremented by one (1) according to the rules specified in Section 5.1.2. If OwnSeqNum is not incremented the routing information might be - considered stale. In this case, the RREP would not reach the RREP + considered stale. In this case, the RREP might not reach the RREP Target. - First, the AddBlk.TargetNode.Address is added to the RREP. The - TargetNode is the ultimate destination of this RREP; the RREQ - OrigNode.Address. - - Next, AddBlk.OrigNode.Address is added to the RREP. The - AddBlk.OrigNode.Address must be a routable IP address. If the RREQ - TargetNode is this DYMO router, its address added to the RREP as the - OrigNode.Address. If the RREQ TargetNode is attached to this DYMO - router, it MUST advertise its address and prefix that contain the - RREQ TargetNode.Address. The RREP OrigNode.AddTLV.SeqNum (OwnSeqNum) - must also added to the RREP. + After any of the sequence number operations above, the RREP + OrigNode.AddTLV.SeqNum (OwnSeqNum) MUST also added to the RREP. Other AddTLVs in the RREP for the OrigNode and TargetNode SHOULD be included and set accordingly. If OrigNode.Dist is included it is set to a number greater than zero (0). The MsgHdr.HopLimit is set to MAX_HOPLIMIT. The IP.DestinationAddress for RREP is set to the IP address of the Route.NextHopAddress for the route to the RREP TargetNode. @@ -851,231 +840,248 @@ Sometimes a DYMO router other than the TargetNode's DYMO router (call it an "intermediate DYMO router") has routing information that can satisfy an incoming RREQ. An intermediate DYMO router can issue a intermediate DYMO router RREP on behalf of the TargetNode's DYMO router. Before creating a intermediate DYMO router RREP, OwnSeqNum SHOULD be incremented by one (1) according to the rules specified in Section 5.1.2. - If OwnSeqNum is not incremented the routing information might be - considered stale by a processing DYMO router. In this case, the RREP - would not reach the RREP Target. + If OwnSeqNum is not incremented the routing information about + ThisNode might be considered stale by a processing DYMO router. In + this case, the RREP would not reach the RREP TargetNode. When an intermediate DYMO router originates a RREP in response to a RREQ on behalf of the TargetNode's DYMO router, it sends the RREP to the RREQ OrigNode with additional routing information (Address, - SeqNum, Prefix, Dist, etc.) about the RREQ TargetNode. Appending + Prefix, SeqNum, Dist, etc.) about the RREQ TargetNode. Appending additional routing information is described in Section 5.3.5. The Intermediate DYMO router SHOULD also issue a RREP to the RREQ TargetNode, so that the RREQ TargetNode receives routing information on how to reach the RREQ OrigNode. When an intermediate DYMO router creates this RREP, it sends a RREP to the RREQ TargetNode with additional routing information (Address, - SeqNum, Dist, Prefix, etc.) about the RREQ OrigNode. + Prefix, SeqNum, Dist, etc.) about the RREQ OrigNode. 5.3.4. RM Processing - Before processing a RM, the DYMO router checks the IP.Destination to - ensure that it was sent to LL MANET ROUTERS. - - When a RM is received the MsgHdr.HopLimit is decremented by one (1). - - For each address (except the TargetNode) in the RM that includes - AddTLV.Dist information, the AddTLV.Dist information is incremented - by at lease one (1). - - Next, ThisNode checks whether AddBlk.OrigNode.Address is an address + ThisNode first checks whether AddBlk.OrigNode.Address is an address handled by this DYMO router. If this node is the originating DYMO router, the RM is dropped. + Before processing a RREQ, the DYMO router checks the IP.Destination + to ensure that it was sent to LL-MANET-ROUTERS [I-D.ietf-manet-iana]. + If the RREQ was not sent to LL-MANET-ROUTERS, it SHOULD be discarded + and further processing stopped. + + Next, ThisNode checks if the AddBlk.OrigNode.Address is a valid + unicast IP address. If the address is not a valid unicast IP + address, the messages MUST be discarded and further processing + stopped. + Next, ThisNode checks whether its routing table has an entry to the AddBlk.OrigNode.Address using longest-prefix matching [RFC1812]. If - a route does not exist and the address is a unicast address, then the - new routing information is considered fresh and a new route table - entry is created and updated as described in Section 5.2.2. If a - route table entry does exists, the incoming routing information is - compared with the route table entry following the procedure described - in Section 5.2.1. If the incoming routing information is considered - superior, the route table entry is updated as described in - Section 5.2.2. + a route does not exist, then the new routing information is + considered fresh and a new route table entry is created and updated + as described in Section 5.2.2. If a route table entry does exists, + the incoming routing information is compared with the route table + entry following the procedure described in Section 5.2.1. If the + incoming routing information is considered superior, the route table + entry is updated as described in Section 5.2.2. After processing the OrigNode's routing information, then each address that is not the TargetNode should be considered for creating and updating routes. Creating and updating routes to other nodes can eliminate RREQ for those IP destinations, in the event that data - needs to be forwarded to the IP destination(s) in the near future. + needs to be forwarded to the IP destination(s) now or in the near + future. - For each of the additional addresses considered, if the address is a - unicast address and the routing table does not have a matching route - using longest-prefix matching, then a route is created and updated as - described in Section 5.2.2. If a route table entry exists, the - incoming routing information is compared with the route table entry - following the procedure described in Section 5.2.1. If the incoming - routing information is considered superior, the route table entry is - updated as described in Section 5.2.2. + For each of the additional addresses considered, ThisNode first + checks the that the address is a unicast IP address. If the address + is not a unicast IP address, the address and all related information + MUST be removed. If the routing table does not have a matching route + for this additional address using longest-prefix matching, then a + route is created and updated as described in Section 5.2.2. If a + route table entry exists, the incoming routing information is + compared with the route table entry following the procedure described + in Section 5.2.1. If the incoming routing information is considered + superior, the route table entry is updated as described in + Section 5.2.2. - If the routing information for an AdditionalNode.Address is not a - unicast address and considered superior, then it is removed from the - RM. Removing this information ensures that the information is not - propagated. + If the routing information for an AdditionalNode.Address is not + considered superior, then it is removed from the RM. Removing this + information ensures that the information is not propagated. At this point, if the routing information for the OrigNode was not - superior then this RM should be discarded and no further processing - of this message is performed. + superior then this RM SHOULD be discarded and no further processing + of this message SHOULD be performed. - If the ThisNode is the DYMO router for the TargetNode and this RM is - a RREQ, then ThisNode responds with a RREP to the RREQ OrigNode (the - new RREP's TargetNode). Alternatively, to distribute routing - information about ThisNode (the RREQ TargetNode) more widely, - ThisNode may optionally perform a RREQ; by issuing a RREQ with - ThisNode listed as the TargetNode, using the procedure in - Section 5.3.1. The procedure for issuing a new RREP is described in - Section 5.3.2. Note: it is important that when creating the RREP, - the RREP OrigNode.Address be the same as the RREQ TargetNode.Address, - if ThisNode is responsible for several addresses. At this point, - ThisNode need not perform any more operations for this RM. + If the ThisNode is the DYMO router responsible for the TargetNode and + this RM is a RREQ, then ThisNode responds with a RREP to the RREQ + OrigNode (the new RREP's TargetNode). The procedure for issuing a + new RREP is described in Section 5.3.2. Note: it is important that + when creating the RREP, the RREP OrigNode.Address for ThisNode be + within the same prefix as the RREQ TargetNode.Address. At this + point, ThisNode need not perform any more operations for this RM. + + Alternatively ThisNode MAY choose to distribute routing information + about ThisNode (the RREQ TargetNode) more widely, ThisNode MAY + optionally perform a route discovery; by issuing a RREQ with ThisNode + listed as the TargetNode, using the procedure in Section 5.3.1. + Note: it is important that when creating the RREQ, the RREQ + OrigNode.Address for ThisNode be within the same prefix as the RREQ + TargetNode.Address. At this point, ThisNode need not perform any + more operations for the original RM. If ThisNode is not the TargetNode, this RM is a RREQ, the RREQ contains the TargetNode.AddTLV.SeqNum, and ThisNode has a forwarding route to the TargetNode with a SeqNum where Route.TargetNode.SeqNum - RREQ.TargetNode.AddTLV.SeqNum >= 0 (using signed 16-bit arithmetic); then this node MAY respond with an intermediate DYMO router RREP. The procedure for performing intermediate DYMO router RREP is - described in Section 5.3.3. At this point, ThisNode need not perform - any more operations for this RM. + described in Section 5.3.3. If an intermediate DYMO router RREP is + sent, ThisNode need not perform any more operations for the original + RM. After processing a RM or creating a new RM, a node can append additional routing information to the RM, according to the procedure described in Section 5.3.5. The additional routing information can help reduce route discoveries at the expense of increased message size. For each address (except the TargetNode) in the RM that includes AddTLV.Dist information, the AddTLV.Dist information is incremented - by a cost value. Advice regarding the cost value is not included in - this specification, it is left up to the implementation. - - The updated distance value will be an measure in determining whether - the routing information is inferior or superior to known information - at other DYMO routers that process this RM. + by at least one (1). The updated distance value will influence + judgment of the routing information (Section 5.2.1) against known + information at other DYMO routers that process this RM. If the resulting distance value for the OrigNode is greater than 65,535, the message is discarded. If the resulting distance value for another node is greater than 65,535, the associated address and its information are removed from the RM. - If this RM's MsgHdr.HopLimit is greater than or equal to one (1), - ThisNode is not the TargetNode, AND this RM is a RREQ, then the - current RM (altered by the procedure defined above) SHOULD be sent to - the LL MANET ROUTERS IP.DestinationAddress. - - By sending the RM ThisNode is advertising that it will provide - routing for IP addresses contained in the outgoing RM based on the - information enclosed. ThisNode MAY choose not to send the RM, though - not resending this RM could decrease connectivity in the network or - result in a non-shortest distance path. - - Some examples of why ThisNode might choose to not send the RM are: if - ThisNode does not want to advertise routing for the contained IP - addresses because it is already congested; if ThisNode has already - issued nearly identical routing information (e.g. ThisNode had - recently issued a RM with nearly the same distance); or if ThisNode - is low on energy and does not want to expend energy for control - message sending or packet forwarding. This type of advanced behavior - is not defined in this specification. + Next, the MsgHdr.HopLimit is decremented by one (1). If this RM's + MsgHdr.HopLimit is greater than or equal to one (1), ThisNode is not + the TargetNode, AND this RM is a RREQ, then the current RM (altered + by the procedure defined above) SHOULD be sent to the + IP.DestinationAddress LL-MANET-ROUTERS [I-D.ietf-manet-iana]. If this RM's MsgHdr.HopLimit is greater than or equal to one (1), ThisNode is not the TargetNode, AND this RM is a RREP, then the current RM is sent to the Route.NextHopAddress for the RREP's TargetNode.Address. If no forwarding route exists to Target.Address, then a RERR is issued to the OrigNode of the RREP. + By sending the updated RM ThisNode is advertising that it will + provide routing for IP addresses contained in the outgoing RM based + on the information enclosed. ThisNode MAY choose not to send the RM, + though not resending this RM could decrease connectivity in the + network or result in a non-shortest distance path. + + Some examples of why ThisNode might choose to not re-issue a RM are: + if ThisNode does not want to advertise routing for the contained IP + addresses because it is already heavily loaded; if ThisNode has + already issued nearly identical routing information (e.g. ThisNode + had recently issued a RM with nearly the same distance); or if + ThisNode is low on energy and does not want to expend energy for + control message sending or packet forwarding. This type of advanced + behavior is not defined in this specification. + 5.3.5. Adding Additional Routing Information to a RM Appending routing information can alleviate route discovery attempts to the nodes whose information is included, if other DYMO routers use this information to update their routing tables. DYMO routers can append routing information to a RM. This option - should be administratively configurable. + should be administratively configurable or intelligently controlled. Prior to appending an address controlled by this DYMO router to a RM, ThisNode MAY increment its OwnSeqNum as defined in Section 5.1.2. If OwnSeqNum is not incremented the appended routing information might - not be considered fresh, when received by nodes with existing routing - information. Incrementation of the sequence number when appending - information to an RM in transit should be administratively - configurable. + not be considered superior, when received by nodes with existing + routing information. Incrementation of the sequence number when + appending information to an RM in transit should be administratively + configurable or intelligently controlled. If an address controlled by this DYMO router includes ThisNode.Dist, it is set to a number greater than zero (0). - For added addresses not controlled by this DYMO router, Route.Dist - can be included if known. If Route.Dist is not known, it cannot be - included. + For added addresses (and their prefixes) not controlled by this DYMO + router, Route.Dist can be included if known. If Route.Dist is not + known, it MUST NOT be included. - Additional information about the appended address(es) can also be - included (e.g. Prefix). + MaxAge information about the appended address(es) MUST be included. + + Additional information (e.g. SeqNum and Dist) about any appended + address(es) SHOULD be included. + + Note that, the routing information about the TargetNode MUST NOT be + added. Also, duplicate address entries SHOULD NOT be added. + Instead, only the best routing information (Section 5.2.1) for a + particular address SHOULD be included. 5.4. Route Discovery - When a source's DYMO router needs to forward a data packet and it - does not have a forwarding route to the IP.DestinationAddress, it - sends a RREQ (described in Section 5.3.1) to discover a route to the - particular destination (TargetNode). + When a source's DYMO router needs to forward a data packet on behalf + of an attached node and it does not have a forwarding route to the + data packet's unicast IP destination address, ThisNode sends a RREQ + (described in Section 5.3.1) to discover a route to the particular + destination (TargetNode). After issuing a RREQ, the OrigNode DYMO router waits for a route to be created to the TargetNode. If a route is not created within RREQ_WAIT_TIME, ThisNode may again try to discover a route by issuing - another RREQ using the procedure defined in Section 5.3.1. + another RREQ using the procedure defined in Section 5.3.1 again. To reduce congestion in a network, repeated attempts at route - discovery for a particular TargetNode should utilize an exponential + discovery for a particular TargetNode SHOULD utilize an exponential backoff. For example, the first time a DYMO router issues a RREQ, it waits RREQ_WAIT_TIME for a route to the TargetNode. If a route is not found within that time, the DYMO router MAY send another RREQ. If a route is not found within two (2) times the current waiting time, another RREQ may be sent, up to a total of RREQ_TRIES. For each additional attempt, the waiting time for the previous RREQ is multiplied by two (2) so that the waiting time conforms to a binary exponential backoff. - Data packets awaiting a route should be buffered by the source's DYMO - router. This buffer should have a fixed limited size + Data packets awaiting a route SHOULD be buffered by the source's DYMO + router. This buffer SHOULD have a fixed limited size (BUFFER_SIZE_PACKETS or BUFFER_SIZE_BYTES) and older data packets SHOULD be discarded first. - Buffering of data packets may have positive or negative impact, and - therefore must be administratively configurable. + Buffering of data packets can have both positive and negative + effects, and therefore buffer settings SHOULD be administratively + configurable or intelligently controlled. If a route discovery has been attempted RREQ_TRIES times without receiving a route to the TargetNode, all data packets destined for the corresponding TargetNode are dropped from the buffer and a Destination Unreachable ICMP message should be delivered to the source. 5.5. Route Maintenance - A RERR MUST be issued if a data packet is to be forwarded and it + A RERR SHOULD be issued if a data packet is to be forwarded and it cannot be delivered to the next hop because no forwarding route for - the IP.Destination exists; RERR generation is described in + the IP.DestinationAddress exists; RERR generation is described in Section 5.5.3. Upon this condition, an ICMP Destination Unreachable message SHOULD NOT be generated unless this router is responsible for the - IP.Destination and that IP.Destination is known to be unreachable. + IP.DestinationAddress and that IP.DestinationAddress is known to be + unreachable. In addition to inability to forward a data packet, a RERR SHOULD be issued immediately after detecting a broken link of an forwarding route to quickly notify DYMO routers that a link break occurred and that certain routes are no longer available. If the route with the broken link has not been used recently (indicated by ROUTE_USED), the RERR SHOULD NOT be generated. 5.5.1. Active Link Monitoring @@ -1084,77 +1090,81 @@ including: o Link layer feedback o Neighborhood discovery [I-D.ietf-manet-nhdp] o Route timeout o Other monitoring mechanisms or heuristics - Upon detecting a link break (or an unreachable next hop) ThisNode - must remove the affected forwarding routes (those with an unreachable - next hop). ThisNode also flags these routes as Broken. For each - broken route a timer for ROUTE_DELETE is set to ROUTE_DELETE_TIMEOUT. + Upon determining that a link is broken (or the next hop is + unreachable), ThisNode MUST remove the affected forwarding routes + (those with an unreachable next hop). ThisNode also flags these + routes as Broken. For each broken route a timer for ROUTE_DELETE is + set to ROUTE_DELETE_TIMEOUT. 5.5.2. Updating Route Lifetimes During Packet Forwarding To avoid removing the forwarding route to reach the IP.SourceAddress, - a node SHOULD set a timeout (ROUTE_USED) to ROUTE_USED_TIMEOUT for + ThisNode SHOULD set a timeout (ROUTE_USED) to ROUTE_USED_TIMEOUT for the route to the IP.SourceAddress upon receiving a data packet. If a timer for ROUTE_DELETE is set, it is removed. To avoid removing the forwarding route to the IP.DestinationAddress - that is being used, a node SHOULD set a timeout (ROUTE_USED) to + that is being used, ThisNode SHOULD set a timeout (ROUTE_USED) to ROUTE_USED_TIMEOUT for the route to the IP.DestinationAddress upon sending a data packet. If a timer for ROUTE_DELETE is set, it is removed. 5.5.3. Route Error Generation A RERR informs DYMO routers that a route to certain destinations is - not available through this node. + not available through ThisNode. When creating a new RERR, the address of first UnreachableNode (IP.DestinationAddress from a data packet or RREP.TargetNode.Address) is inserted into an Address Block AddBlk.UnreachableNode.Address. If - a value for the UnreachableNode's SeqNum - (UnreachableNode.AddTLV.SeqNum) is known, it SHOULD be placed in the - RERR. The MsgHdr.HopLimit is set to MAX_HOPLIMIT. + a prefix is known for the UnreachableNode.Address, it SHOULD be + included. Otherwise, the UnreachableNode.Address assumed to be a + host address with a full length prefix. If a value for the + UnreachableNode's SeqNum (UnreachableNode.AddTLV.SeqNum) is known, it + SHOULD be placed in the RERR. The MsgHdr.HopLimit is set to + MAX_HOPLIMIT. Additional UnreachableNodes that require the same unavailable link (routes with the same Route.NextHopAddress and Route.NextHopInterface) SHOULD be added to the RERR, as additional - AddBlk.UnreachableNode.Address. The SeqNum if known SHOULD also be - included. Appending UnreachableNode information notifies each - processing node of additional routes that are no longer available. - This option SHOULD be administratively configurable. + AddBlk.UnreachableNode.Address entries with their associated prefix. + The SeqNum if known SHOULD also be included. Appending + UnreachableNode information notifies each processing node of + additional routes that are no longer available. This option SHOULD + be administratively configurable or intelligently controlled. If SeqNum information is not known or not included in the RERR, all nodes processing the RERR will assume their routing information - associated with the UnreachableNode is no longer valid and flags - those routes as broken. + associated with the UnreachableNode is no longer valid and flag those + routes as broken. - The RERR is sent to the IP.DestinationAddress LL MANET ROUTERS. - Sending the RERR to the LL MANET ROUTERS address notifies nearby - nodes that might depend on the now broken link. + The RERR is sent to the IP.DestinationAddress LL-MANET-ROUTERS + [I-D.ietf-manet-iana]. Sending the RERR to the LL-MANET-ROUTERS + address notifies nearby nodes that might depend on the now broken + link. - The packet or message that forced generation of this RERR is - discarded. + At this point, the packet or message that forced generation of this + RERR SHOULD be discarded. 5.5.4. RERR Processing - Before processing a RERR, the DYMO router checks the IP.Destination - to ensure that it is addressed to LL MANET ROUTERS. - - Upon reception of a RERR the MsgHdr.HopLimit is decremented by one - (1). + Before processing a RERR, the DYMO router checks the + IP.DestinationAddress to ensure that it is addressed to LL-MANET- + ROUTERS [I-D.ietf-manet-iana]. When a DYMO router processes a RERR, it processes each UnreachableNode's information. The processing DYMO router removes the forwarding route, sets the broken flag, and a timer for ROUTE_DELETE is set to ROUTE_DELETE_TIMEOUT for each UnreachableNode.Address found using longest prefix matching that meet all of the following conditions: 1. The UnreachableNode.Address is a unicast address. @@ -1162,210 +1172,202 @@ IP.SourceAddress. 3. The Route.NextHopInterface is the same as the interface on which the RERR was received. 4. The Route.SeqNum is zero (0), unknown, OR the UnreachableNode.SeqNum is zero (0), unknown, OR Route.SeqNum - UnreachableNode.SeqNum <= 0 (using signed 16-bit arithmetic). During processing if Route.SeqNum is zero (0) or unknown and - Unreachable.SeqNum exists in the RERR, then Route.SeqNum can be set + Unreachable.SeqNum exists in the RERR, then Route.SeqNum MAY be set to Unreachable.SeqNum. Setting Route.SeqNum can reduce future RRER processing and forwarding. Each UnreachableNode that did not result in a broken route is removed from the RERR, since propagation of this information will not result in any benefit. Any other information (AddTLVs) associated with the removed address(es) is also removed. After processing if Route.SeqNum is known and an Unreachable.SeqNum is not included in the RERR, then Route.SeqNum (i.e. - Unreachable.SeqNum) can be added to the RERR. Including + Unreachable.SeqNum) MAY be added to the RERR. Including Unreachable.SeqNum can reduce future RRER processing and forwarding. If no UnreachableNode addresses remain in the RERR, no other processing is required and the RERR is discarded. - If this RERR's MsgHdr.HopLimit is greater than one (1) and at least - one unreachable node address remains in the RERR, then the updated - RERR is sent to the IP.DestinationAddress LL MANET ROUTERS. + If processing continues, the MsgHdr.HopLimit is decremented by one + (1). Further, if this RERR's new MsgHdr.HopLimit is greater than one + (1) and at least one unreachable node address remains in the RERR, + then the updated RERR is sent to the IP.DestinationAddress LL-MANET- + ROUTERS [I-D.ietf-manet-iana]. 5.6. Unknown Message & TLV Types If a message with an unknown type is received, the message is discarded. - If a message contains TLVs of an unknown type, a node ignores these - during processing. The processing node can remove these TLVs from - any resulting transmitted messages. The behavior for unknown TLV - types should be administratively configurable. + For processing of messages that contain unknown TLV types, operation + should be administratively controlled. 5.7. Advertising Network Addresses - Any DYMO router advertises a network address by using a PREFIX_LENGTH - TLV [I-D.ietf-manet-packetbb]. Any nodes (other than the advertising - DYMO router) within the advertised prefix SHOULD NOT participate in - the DYMO protocol directly and these nodes MUST be reachable by - forwarding packets to the DYMO router advertising connectivity. - Nodes other than the advertising DYMO router that do participate in - DYMO must forward the DYMO control packets to the advertising DYMO - router. For example, A.B.C.1 with a prefix length of 24 indicates + DYMO routers advertise specify the prefix length for each advertised + address. Any nodes (other than the advertising DYMO router) within + the advertised prefix MUST NOT participate in the DYMO protocol + directly. For example, A.B.C.1 with a prefix length of 24 indicates all nodes with the matching A.B.C.X are reachable through the DYMO router with address A.B.C.1. -5.8. Simple Internet Attachment and Gatewaying +5.8. Simple Internet Attachment Simple Internet attachment consists of a stub network of MANET - routers connected to the Internet via a single Internet gateway node. - DYMO can operate with multiple gateways, but such behavior is not - specified in this document. + routers connected to the Internet via a single Internet DYMO router + (IDR). The Internet may be connected via multiple DYMO routers, but + such behavior is not specified in this document. - The gateway is responsible for responding to RREQs for TargetNodes - outside its configured DYMO prefix, as well as delivering packets to - destinations outside the MANET. + The IDR is responsible for responding to RREQs for DYMO routers on + behalf of TargetNodes on the Internet, as well as delivering packets + to destinations on the Internet. /--------------------------\ / Internet \ \ / \------------+-------------/ - Gateway's | - Advertised | A.B.C.X/24 + | + Routable & | + Topologically | A.B.C.X/24 + Correct | Prefix | +-----+-----+ - | DYMO | - /------| Internet |--------\ - / | Gateway | \ + | Internet | + /------| DYMO |--------\ + / | Router | \ / | A.B.C.1 | \ | +-----------+ | | DYMO Region | | | | +--------------+ | | | DYMO Router | | | | A.B.C.2 | | | +--------------+ | | +--------------+ | | | DYMO Router | | | | A.B.C.3 | | \ +--------------+ / \ / \---------------------------/ Figure 7: Simple Internet Attachment Example DYMO routers wishing to be reachable from nodes in the Internet MUST - have IP addresses within the gateway's configured and advertised - prefix. Given a node with a globally routeable address or care-of - address handled by the gateway, the gateway is responsible for - routing and forwarding packets received from the Internet destined - for nodes inside its MANET. + have IP addresses within the IDR's routable and topologically correct + prefix. Given a node with a routeable address or care-of address + handled by the IDR, the IDR is responsible for routing and forwarding + packets received from the Internet destined for nodes inside its + MANET. - When DYMO router within the MANET want to send messages to nodes in - the Internet, they simply issue RREQ for those - IP.DestinationAddresses. The gateway is responsible for responding - to RREQ on behalf of the Internet destinations and maintaining their - associated sequence number. + When DYMO router within the MANET want to send packets to a node on + the Internet, they simply issue RREQ for those IP Destination + Addresses; using normal DYMO route discovery. The IDR is responsible + for properly responding to RREQ on behalf of the Internet + destinations, and maintaining their associated sequence number(s). - For an Internet gateway and other DYMO routers that maintain the - sequence number on behalf of other nodes, these routers must be - administratively configurable to know the IP addresses for which they - must generate DYMO messages and maintain OwnSeqNum. + For an IDR and other DYMO routers that maintain the sequence number + on behalf of other nodes, these routers MUST know the IP addresses + for which they MUST generate DYMO messages and maintain OwnSeqNum. + Likewise, they MUST be capable of advertising an address within the + same prefix as these IP addresses. Alternatively, they may behave as + a proxy on behalf of Internet destinations. 5.9. Multiple Interfaces DYMO may be used with multiple interfaces; therefore, the particular - interface over which packets arrive must be known whenever a packet + interface over which packets arrive MUST be known whenever a packet is received. Whenever a new route is created, the interface through which the Route.Address can be reached is also recorded in the route table entry. When multiple interfaces are available, a node transmitting a packet - with IP.DestinationAddress set to LL MANET ROUTERS SHOULD send the + with IP.DestinationAddress set to LL-MANET-ROUTERS SHOULD send the packet on all interfaces that have been configured for DYMO operation. - Similarly, DYMO routers should subscribe to LL MANET ROUTERS on all + Similarly, DYMO routers should subscribe to LL-MANET-ROUTERS on all their DYMO interfaces. -5.10. Packet/Message Generation Limits +5.10. DYMO Control Packet/Message Generation Limits - To avoid congestion, a node's rate of packet/message generation - should be limited. The rate and algorithm for limiting messages is - left to the implementor and should be administratively configurable. - Messages should be discarded in the following order of preferences - RREQ, RREP, and finally RERR. + To ensure predictable control overhead, DYMO router's rate of packet/ + message generation SHOULD be limited. The rate and algorithm for + limiting messages is left to the implementor and should be + administratively configurable or intelligently controlled. DYMO + control messages SHOULD be discarded in the following order of + preferences RREQ, RREP, and finally RERR. 6. Configuration Parameters and Other Administrative Options Suggested Parameter Values - +------------------------------+------------------------+ + +------------------------------+-------------------+ | Name | Value | - +------------------------------+------------------------+ + +------------------------------+-------------------+ | MAX_HOPLIMIT | 10 hops | - | NET_TRAVERSAL_TIME | 1000 milliseconds | | ROUTE_TIMEOUT | 5 seconds | - | ROUTE_AGE_MIN_TIMEOUT | NET_TRAVERSAL_TIME | + | ROUTE_AGE_MIN_TIMEOUT | 1 second | | ROUTE_AGE_MAX_TIMEOUT | 60 seconds | - | ROUTE_NEW_TIMEOUT | ROUTE_TIMEOUT | | ROUTE_USED_TIMEOUT | ROUTE_TIMEOUT | | ROUTE_DELETE_TIMEOUT | 2 * ROUTE_TIMEOUT | - | ROUTE_RREQ_WAIT_TIME | 2 * NET_TRAVERSAL_TIME | + | ROUTE_RREQ_WAIT_TIME | 2 seconds | | RREQ_TRIES | 3 tries | | UNICAST_MESSAGE_SENT_TIMEOUT | 1 second | - +------------------------------+------------------------+ + +------------------------------+-------------------+ Table 2 + These suggested values work well for small and medium well connected - networks with infrequent topology changes. These parameters should + networks with infrequent topology changes. These parameters SHOULD be administratively configurable for the network where DYMO is used. Ideally, for networks with frequent topology changes the DYMO parameters should be adjusted using either experimentally determined values or dynamic adaptation. For example, in networks with infrequent topology changes ROUTE_USED_TIMEOUT may be set to a much larger value. In addition to the parameters above several administrative options - exist. The following table enumerates several of the options and - suggested values. + exist. Many of these options can be administratively controlled, but + they may be better served by intelligent control. The following + table enumerates several of the options. - Suggested Options Settings + Important Settings - +-------------------------------------+----------------------------+ - | Name | Value | - +-------------------------------------+----------------------------+ - | RESPONSIBLE_ADDRESSES | Self or Prefix | - | DYMO_INTERFACES | User Specified | - | INCLUDE_INFORMATION | Yes-SeqNum,Dist,Prefix | - | APPEND_ADDRESS | Yes - RREQ & RREP | - | APPEND_OWN_ADDRESS_INCREMENT_SEQNUM | Yes for RREQ | - | GENERATE_RERR_IMMEDIATELY | No | - | RERR_INCLUDE_ALL_UNREACHABLES | Yes | - | UNKNOWN_TYPE_HANDLING | Ignore | - | BUFFER_SIZE_PACKETS | 50 packets | - | BUFFER_SIZE_BYTES | 1500 * BUFFER_SIZE_PACKETS | - +-------------------------------------+----------------------------+ + +-----------------------------------------+ + | Name | + +-----------------------------------------+ + | RESPONSIBLE_ADDRESSES | + | DYMO_INTERFACES | + | UNKNOWN_TLV_TYPE_HANDLING | + | ROUTE_DISCOVERY_DATA_PACKET_BUFFER_SIZE | + +-----------------------------------------+ Table 3 7. IANA Considerations - DYMO requires a UDP port number to carry protocol packets - MANET - [I-D.ietf-manet-iana]. DYMO also requires the link-local multicast - address LL MANET ROUTERS [I-D.ietf-manet-iana]. + In its default mode of operation, DYMO uses the UDP port MANET + [I-D.ietf-manet-iana] to carry protocol packets. DYMO also uses the + link-local multicast address LL-MANET-ROUTERS [I-D.ietf-manet-iana]. This section specifies several messages types, message tlv-types, and address tlv-types. - Future types will be allocated using standard actions as described in - [RFC2434]. - 7.1. DYMO Message Type Specification DYMO Message Types +------------------------+----------+ | Name | Type | +------------------------+----------+ | Route Request (RREQ) | 10 - TBD | | Route Reply (RREP) | 11 - TBD | | Route Error (RERR) | 12 - TBD | @@ -1374,133 +1376,136 @@ Table 4 7.2. Packet and Message TLV Type Specification Packet TLV Types +-------------------+------+--------+-------------------------------+ | Name | Type | Length | Value | +-------------------+------+--------+-------------------------------+ | Unicast Response | 10 - | 0 | Indicates to the processing | - | Request | TBD | | node that the previous hop | + | Request | TBD | octets | node that the previous hop | | | | | (IP.SourceAddress) expects a | | | | | unicast message within | | | | | UNICAST_MESSAGE_SENT_TIMEOUT. | | | | | Any unicast packet will serve | | | | | this purpose, and it MAY be | | | | | an ICMP REPLY message. If a | | | | | message is not sent, then the | - | | | | previous hop may assume that | + | | | | previous hop can assume that | | | | | the link is unidirectional | - | | | | and may blacklist the link to | + | | | | and MAY blacklist the link to | | | | | this node. | +-------------------+------+--------+-------------------------------+ Table 5 7.3. Address Block TLV Specification Address Block TLV Types - +----------------+------+---------+---------------------------------+ + +---------------+--------------+--------+---------------------------+ | Name | Type | Length | Value | - +----------------+------+---------+---------------------------------+ - | DYMOSeqNum | 10 - | 16 bits | The DYMO sequence num | - | | TBD | (2 | associated with this address. | - | | | bytes) | The sequence number may be the | - | | | | last known sequence number. | - | Distance | 11 - | up to | A metric of the distance | - | | TBD | 16 bits | traversed by the information | - | | | (2 | associated with this address. | - | | | bytes) | | - | MaxAge | 12 - | | The maximum amount of time that | - | | TBD | | information can be maintained | - | | | | before being deleted. This TLV | - | | | | conforms to | - | | | | [I-D.ietf-manet-timetlv] | - | | | | VALIDITY_TIME TLV, except that | - | | | | the TLV is attached to | - | | | | addresses. | - +----------------+------+---------+---------------------------------+ + +---------------+--------------+--------+---------------------------+ + | DYMOSeqNum | 10 - TBD | up to | The DYMO sequence num | + | | | 2 | associated with this | + | | | octets | address. The sequence | + | | | | number may be the last | + | | | | known sequence number. | + | Distance | 11 - TBD | up to | A metric of the distance | + | | | 2 | traversed by the | + | | | octets | information associated | + | | | | with this address. | + | VALIDITY_TIME | TBD | | The maximum amount of | + | - AKA MaxAge | [I-D.ietf-ma | | time that information can | + | | n et-timetlv | | be maintained before | + | | ] | | being deleted. The | + | | | | VALIDITY_TIME TLV is | + | | | | defined in | + | | | | [I-D.ietf-manet-timetlv]. | + +---------------+--------------+--------+---------------------------+ Table 6 8. Security Considerations Currently, DYMO does not specify any special security measures. - In situations where confidentiality o DYMO messages is important, + In situations where confidentiality of DYMO messages is important, traditional cryptographic techniques can be applied. Securing routing information integrity will likely require DYMO routers to authenticate DYMO messages upon reception. Also, since routing information is distributed hop-by-hop, DYMO routers will also likely need to authenticate the source of the routing information, the source's DYMO router. Note that is important that any confidentiality and integrity algorithms used permit multiple receivers to process the message, - since all DYMO messaging is multicast. + since much of DYMO's messaging is multicast. 9. Acknowledgments DYMO is a descendant of the design of previous MANET reactive protocols, especially AODV [RFC3561] and DSR [RFC4728]. Changes to previous MANET reactive protocols stem from research and implementation experiences. Thanks to Elizabeth Belding-Royer for her long time authorship of DYMO. Additional thanks to Luke Klein- Berndt, Pedro Ruiz, Fransisco Ros, Koojana Kuladinithi, Ramon Caceres, Thomas Clausen, Christopher Dearlove, Seung Yi, Romain Thouvenin, Tronje Krop, Henner Jakob, Alexandru Petrescu, Christoph Sommer, Cong Yuan, and Lars Kristensen for reviewing of DYMO, as well as several specification suggestions. 10. References 10.1. Normative References [I-D.ietf-manet-iana] - Chakeres, I., "IANA Allocations for Mobile Ad hoc Network - (MANET) Protocols", draft-ietf-manet-iana-06 (work in - progress), October 2007. + Chakeres, I., "IANA Allocations for MANET Protocols", + draft-ietf-manet-iana-07 (work in progress), + November 2007. [I-D.ietf-manet-packetbb] - Clausen, T., "Generalized MANET Packet/Message Format", - draft-ietf-manet-packetbb-10 (work in progress), - October 2007. + Clausen, T., Dearlove, C., Dean, J., and C. Adjih, + "Generalized MANET Packet/Message Format", + draft-ietf-manet-packetbb-11 (work in progress), + November 2007. [I-D.ietf-manet-timetlv] Clausen, T. and C. Dearlove, "Representing multi-value - time in MANETs", draft-ietf-manet-timetlv-02 (work in - progress), August 2007. + time in MANETs", draft-ietf-manet-timetlv-04 (work in + progress), November 2007. [RFC1812] Baker, F., "Requirements for IP Version 4 Routers", RFC 1812, June 1995. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. - [RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an - IANA Considerations Section in RFCs", BCP 26, RFC 2434, - October 1998. + [RFC5082] Gill, V., Heasley, J., Meyer, D., Savola, P., and C. + Pignataro, "The Generalized TTL Security Mechanism + (GTSM)", RFC 5082, October 2007. 10.2. Informative References [I-D.ietf-manet-jitter] - Clausen, T., "Jitter considerations in MANETs", - draft-ietf-manet-jitter-02 (work in progress), - August 2007. + Clausen, T., Dearlove, C., and B. Adamson, "Jitter + considerations in Mobile Ad Hoc Networks (MANETs)", + draft-ietf-manet-jitter-04 (work in progress), + December 2007. [I-D.ietf-manet-nhdp] - Clausen, T., "MANET Neighborhood Discovery Protocol - (NHDP)", draft-ietf-manet-nhdp-04 (work in progress), - July 2007. + Clausen, T., Dearlove, C., and J. Dean, "MANET + Neighborhood Discovery Protocol (NHDP)", + draft-ietf-manet-nhdp-05 (work in progress), + December 2007. [Perkins99] Perkins, C. and E. Belding-Royer, "Ad hoc On-Demand Distance Vector (AODV) Routing", Proceedings of the 2nd IEEE Workshop on Mobile Computing Systems and Applications, New Orleans, LA, pp. 90-100, February 1999. [RFC3561] Perkins, C., Belding-Royer, E., and S. Das, "Ad hoc On- Demand Distance Vector (AODV) Routing", RFC 3561, @@ -1514,32 +1519,28 @@ Ian D Chakeres Motorola Bangalore India Email: ian.chakeres@gmail.com URI: http://www.ianchak.com/ Charles E. Perkins - Palo Alto Systems Research Center - 975 Page Mill Road, Suite 200 - Palo Alto, CA 94304-1003 + Palo Alto, CA USA - Phone: +1-650-496-4402 - Fax: +1-650-739-0779 - Email: charles.perkins@nokia.com + Email: charliep@computer.org Full Copyright Statement - Copyright (C) The IETF Trust (2007). + Copyright (C) The IETF Trust (2008). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF