draft-ietf-manet-dymo-04.txt   draft-ietf-manet-dymo-05.txt 
Mobile Ad hoc Networks Working I. Chakeres Mobile Ad hoc Networks Working I. Chakeres
Group Boeing Group Boeing
Internet-Draft C. Perkins Internet-Draft C. Perkins
Expires: September 6, 2006 Nokia Expires: December 22, 2006 Nokia
March 5, 2006 June 20, 2006
Dynamic MANET On-demand (DYMO) Routing Dynamic MANET On-demand (DYMO) Routing
draft-ietf-manet-dymo-04 draft-ietf-manet-dymo-05
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Copyright Notice Copyright Notice
Copyright (C) The Internet Society (2006). Copyright (C) The Internet Society (2006).
Abstract Abstract
The Dynamic MANET On-demand (DYMO) routing protocol is intended for The Dynamic MANET On-demand (DYMO) routing protocol is intended for
use by mobile nodes in wireless multihop networks. It offers use by mobile nodes in wireless multihop networks. It offers
adaptation to changing network topology and determines unicast routes adaptation to changing network topology and determines unicast routes
between nodes within the network on-demand. between nodes within the network on-demand.
Table of Contents Table of Contents
1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Applicability . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Data Structures . . . . . . . . . . . . . . . . . . . . . . . 6
3. Data Structures . . . . . . . . . . . . . . . . . . . . . . . 8 4.1. Route Table Entry . . . . . . . . . . . . . . . . . . . . 6
3.1. Route Table Entry . . . . . . . . . . . . . . . . . . . . 8 4.2. DYMO Messages . . . . . . . . . . . . . . . . . . . . . . 7
3.2. DYMO Messages . . . . . . . . . . . . . . . . . . . . . . 10 4.2.1. Generalized MANET Packet and Message Structure . . . . 7
3.2.1. Generalized MANET Packet and Message Structure . . . . 10 4.2.2. Routing Message (RM) . . . . . . . . . . . . . . . . . 8
3.2.2. Routing Message (RM) . . . . . . . . . . . . . . . . . 10 4.2.3. Route Error (RERR) . . . . . . . . . . . . . . . . . . 10
3.2.3. Route Error (RERR) . . . . . . . . . . . . . . . . . . 12 5. Detailed Operation . . . . . . . . . . . . . . . . . . . . . . 12
5.1. DYMO Sequence Numbers . . . . . . . . . . . . . . . . . . 12
4. Detailed Operation . . . . . . . . . . . . . . . . . . . . . . 14 5.1.1. Maintaining A Node's Own Sequence Number . . . . . . . 12
4.1. Sequence Numbers . . . . . . . . . . . . . . . . . . . . . 14 5.1.2. Incrementing a Sequence Number . . . . . . . . . . . . 13
4.1.1. Maintaining a Sequence Number . . . . . . . . . . . . 14 5.1.3. Sequence Number Rollover . . . . . . . . . . . . . . . 13
4.1.2. Incrementing a Sequence Number . . . . . . . . . . . . 14 5.1.4. Actions After Sequence Number Loss . . . . . . . . . . 13
4.1.3. Sequence Number Rollover . . . . . . . . . . . . . . . 14 5.2. DYMO Routing Table Operations . . . . . . . . . . . . . . 13
4.1.4. Actions After Sequence Number Loss . . . . . . . . . . 14 5.2.1. Judging New Routing Information's Usefulness . . . . . 13
4.2. DYMO Routing Table Operations . . . . . . . . . . . . . . 14 5.2.2. Updating a Route Table Entry with Fresh Routing
4.2.1. Creating or Updating a Route Table Entry from Information . . . . . . . . . . . . . . . . . . . . . 14
Routing Message Information . . . . . . . . . . . . . 14 5.2.3. Route Table Entry Timeouts . . . . . . . . . . . . . . 15
4.2.2. Route Table Entry Timeouts . . . . . . . . . . . . . . 16 5.3. Routing Message . . . . . . . . . . . . . . . . . . . . . 15
4.3. Routing Message . . . . . . . . . . . . . . . . . . . . . 16 5.3.1. RREQ Creation . . . . . . . . . . . . . . . . . . . . 15
4.3.1. Routing Message Creation . . . . . . . . . . . . . . . 16 5.3.2. RREP Creation . . . . . . . . . . . . . . . . . . . . 16
4.3.2. Routing Message Processing . . . . . . . . . . . . . . 16 5.3.3. RM Processing . . . . . . . . . . . . . . . . . . . . 16
4.3.3. Appending Additional Routing Information to an 5.3.4. Adding Additional Routing Information to a RM . . . . 18
Existing Routing Message . . . . . . . . . . . . . . . 17 5.4. Route Discovery . . . . . . . . . . . . . . . . . . . . . 18
4.4. Route Discovery . . . . . . . . . . . . . . . . . . . . . 18 5.5. Route Maintenance . . . . . . . . . . . . . . . . . . . . 19
4.5. Route Maintenance . . . . . . . . . . . . . . . . . . . . 18 5.5.1. Active Link Monitoring . . . . . . . . . . . . . . . . 19
4.5.1. Active Link Monitoring . . . . . . . . . . . . . . . . 18 5.5.2. Updating Route Lifetimes during Packet Forwarding . . 20
4.5.2. Updating Route Lifetimes . . . . . . . . . . . . . . . 19 5.5.3. Route Error Generation . . . . . . . . . . . . . . . . 20
4.5.3. Route Error Generation . . . . . . . . . . . . . . . . 19 5.5.4. Route Error Processing . . . . . . . . . . . . . . . . 21
4.5.4. Route Error Processing . . . . . . . . . . . . . . . . 20 5.6. General DYMO Packet and Message Processing . . . . . . . . 21
4.6. General DYMO Packet and Message Processing . . . . . . . . 21 5.6.1. Receiving Packets . . . . . . . . . . . . . . . . . . 21
4.6.1. Packet Processing . . . . . . . . . . . . . . . . . . 21 5.6.2. Processing Unknown Message and TLV Types . . . . . . . 21
4.6.2. Generic Message Pre-processing . . . . . . . . . . . . 21 5.7. Network Addresses . . . . . . . . . . . . . . . . . . . . 22
4.6.3. Processing Unknown Message and TLV Types . . . . . . . 21 5.8. Simple Internet Attachment and Gatewaying . . . . . . . . 22
4.6.4. Generic Message Post-processing . . . . . . . . . . . 21 5.9. Multiple Interfaces . . . . . . . . . . . . . . . . . . . 23
4.6.5. DYMO Control Packet Transmission . . . . . . . . . . . 21 5.10. Packet Generation Limits . . . . . . . . . . . . . . . . . 24
4.7. Routing Prefix . . . . . . . . . . . . . . . . . . . . . . 21 6. Configuration Parameters . . . . . . . . . . . . . . . . . . . 24
4.8. Simple Internet Attachment and Gatewaying . . . . . . . . 22 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 24
4.9. Multiple Interfaces . . . . . . . . . . . . . . . . . . . 22 7.1. DYMO Message Type Specification . . . . . . . . . . . . . 25
4.10. Packet Generation Limits . . . . . . . . . . . . . . . . . 23 7.2. Packet TLV Type Specification . . . . . . . . . . . . . . 25
7.3. Address Block TLV Specification . . . . . . . . . . . . . 26
5. Configuration Parameters . . . . . . . . . . . . . . . . . . . 24 8. Security Considerations . . . . . . . . . . . . . . . . . . . 26
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 27
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 27
7. Security Considerations . . . . . . . . . . . . . . . . . . . 26 10.1. Normative References . . . . . . . . . . . . . . . . . . . 27
10.2. Informative References . . . . . . . . . . . . . . . . . . 28
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 27
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.1. Normative References . . . . . . . . . . . . . . . . . . . 28
9.2. Informative References . . . . . . . . . . . . . . . . . . 28
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 29 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 29
Intellectual Property and Copyright Statements . . . . . . . . . . 30 Intellectual Property and Copyright Statements . . . . . . . . . . 30
1. Overview 1. Overview
The Dynamic MANET On-demand (DYMO) routing protocol enables reactive, The Dynamic MANET On-demand (DYMO) routing protocol enables reactive,
multihop routing between participating nodes that wish to multihop routing between participating nodes that wish to
communicate. The basic operations of the DYMO protocol are route communicate. The basic operations of the DYMO protocol are route
discovery and route management. During route discovery the discovery and route management. During route discovery the
originating node initiates dissemination of a Route Request (RREQ) originating node initiates dissemination of a Route Request (RREQ)
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directions. directions.
In order to react to changes in the network topology nodes maintain In order to react to changes in the network topology nodes maintain
their routes and monitor their links. When a data packet is received their routes and monitor their links. When a data packet is received
for a route or link that is no longer available the source of the for a route or link that is no longer available the source of the
packet is notified. A Route Error (RERR) is sent to the packet packet is notified. A Route Error (RERR) is sent to the packet
source to indicate the current route is broken. Once the source source to indicate the current route is broken. Once the source
receives the RERR, it can perform route discovery if it still has receives the RERR, it can perform route discovery if it still has
packets to deliver. packets to deliver.
In order to enable extension of the base specification, DYMO uses the
generalized MANET packet and message format [5]. Additionally, by
following the defined default behavior for nodes not understanding a
particular type of information, future enhancements are handled in an
understood and predetermined fashion.
DYMO uses sequence numbers as they have been proven to ensure loop DYMO uses sequence numbers as they have been proven to ensure loop
freedom [3]. Sequence numbers enable nodes to determine the order of freedom [Perkins99]. Sequence numbers enable nodes to determine the
DYMO route discovery messages, thereby avoiding use of stale routing order of DYMO route discovery messages, thereby avoiding use of stale
information. routing information.
All DYMO messages conform to the generalized MANET message and packet
format [5] and are transmitted via UDP on port TBD.
2. Terminology 2. Applicability
DYMO Sequence Number (SeqNum) The DYMO routing protocol is designed for mobile ad hoc networks in
small, medium, and large node populations. DYMO handles all mobility
ranges. DYMO can handle various traffic patterns, but is most suited
for sparse traffic sources and destinations. DYMO is designed for
network where trust is assumed, since it depends on nodes properly
forwarding traffic to the next hop toward the destination on behalf
of the source.
A DYMO Sequence Number is 16-bit number maintained by each DYMO is applicable to memory constrained devices, since little
node, and it is used to ensure loop-free routes. routing state needs to be maintained. Only routing information
related to active destinations must be maintained, as opposed to
other routing protocols where routing information to all destinations
or a large population destinations must be maintained.
Hop Count (HopCnt) 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.
The number of hops a particular message or piece of information 3. Terminology
has traversed.
IP Destination Address (IPDestinationAddress) The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
NOT","SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in
this document are to be interpreted as described in RFC2119
[RFC2119].
The destination of a packet, determined by examining the IP This document defines the following terminology:
header.
IP Source Address (IPSourceAddress) DYMO Sequence Number (SeqNum)
A DYMO Sequence Number is maintained by each node. This sequence
number is used to identify the freshness of related routing
information and to ensure loop-free routes.
The source of a packet, determined by examining the IP header. Hop Count (HopCnt)
The number of IP hops a message or piece of information must
traverse to reach the node holding this information.
MANETcast Originator (Orig)
The originator is the node that created a DYMO Message in an
effort to disseminate information.
Packet transmission to all neighboring MANET routers. Route Error (RERR)
MANETcast packets should be sent with an IPDestinationAddress A node generates a RERR to disseminate that it does not have valid
of IPv4 TBD (IPv6 TBD), the MANETcastAddress. route to a particular destination, or set of destinations.
Originator (Orig) Route Reply (RREP)
Upon receiving a RREQ during route discovery, the target node
generates a Route Reply (RREP). A RREP is used to disseminate
routing information, on how to reach the target, to nodes between
the target and the RREQ originator.
The Originator is the node that created a Routing Message in an Route Request (RREQ)
effort to disseminate and possibly learn new routing A node generates a RREQ to discover a valid route to a particular
information. destination, called the target. A RREQ also disseminates routing
information on how to reach the originator of the RREQ.
Prefix Target
The target node is the ultimate destination of a message. For
RREQ the target is the desired destination. For RREP the target
is the originator of the RREQ.
A Prefix indicates that an address is a network address, rather Valid Route
than a host address. If a Prefix is omitted, the address is A valid route is a known route where the Route.ValidTimeout is
assumed to be a host address. greater than the current time. Valid routes may be used to
forward data.
Routing Message (RM) When describing DYMO messages, information found in the:
A DYMO message that is used to distribute routing information. IP header is proceeded with 'IP.'
Route Invalidation UDP header is proceeded with 'UDP.'
Disabling the use of a route; causing it to be unavailable for packetbb message header is proceeded with 'MsgHdr.'
forwarding data.
Route Reply (RREP) packetbb message TLVs is proceeded with 'MsgTLV.'
Upon receiving a RREQ during route discovery, the target node packetbb address blocks is proceeded with 'AddBlk.'
generates a Route Reply (RREP). A RREP is used to disseeminate
routing information on how to reach the Target. A RREP is a RM
with a unicast IPDestinationAddress, indicating that this RM is
to be unicast hop-by-hop toward the Target.
Route Error (RERR) packetbb address block TLVs is proceeded with 'AddTLV.'
A node generates a Route Error (RERR) to disseminate that it 4. Data Structures
does not have correct routing information about a particular
destination, or set of destinations. A RERR is most often
generated in response to a request to forward a data packet for
which the current node does not have a valid route.
Route Request (RREQ) 4.1. Route Table Entry
A node generates a Route Request (RREQ) to discover a valid The route table entry is a conceptual data structure.
route to a particular destination (Target). A RREQ is used to Implementations may use any internal representation that conforms to
disseminate routing information on how to reach the Originator the semantics of a route as specified in this document. The number
of the RREQ. A RREQ is simply a RM with the MANETcastAddress zero (0) is reserved and can be used to indicate that the field value
in the IPDestinationAddress field of the IP packet, causing for this routing entry is unknown or invalid.
distribution to all neighboring DYMO routers.
Target A routing table entry has the following fields:
The Target is the ultimate destination of a message. For RREQ Route.Address
this will be the desired destination. For RREP this will be The IP destination address of the node associated with the routing
the Originator of the RREQ. table entry.
Valid Route Route.SeqNum
The DYMO SeqNum associated with this routing information.
A known route where the Route.ValidTimeout is greater than the Route.NextHopAddress
current time. The IP address of the next node on the path toward the
Route.Address.
3. Data Structures Route.NextHopInterface
The interface used to send packets toward the Route.Address.
3.1. Route Table Entry Route.ValidTimeout
The time at which a route table entry is no longer valid.
The route table entry is a conceptual data structure. Route.DeleteTimeout
Implementations may use any internal representation that conforms to If the current time is after Route.DeleteTimeout the corresponding
the semantics of a route as specified in this document. routing table entry MUST be deleted.
o Route.DestAddress The following fields are optional:
o Route.DeleteTimeout Route.HopCnt
The number of intermediate node hops traversed before reaching the
Route.Address node.
o Route.HopCnt Route.IsInternetGateway
1-bit selector indicating whether the Route.Address is a an
Internet gateway, see Section 5.8.
o Route.IsGateway 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 prefix is set to zero (0), unknown, or equal to the
address length in bits, this address is a host address. The
definition of Route.Prefix is different for gateways; entries with
Route.IsInternetGateway set to one (1), seeSection 5.8.
o Route.NextHopAddress Route.Used
1-bit selector indicating whether this Route has been used to
forward data toward the destination.
o Route.NextHopInterface Not including this optional information may result in sub-optimal
performance, but it is not required for correct protocol operation.
o Route.Prefix 4.2. DYMO Messages
o Route.SeqNum 4.2.1. Generalized MANET Packet and Message Structure
o Route.ValidTimeout All DYMO messages conform to the generalized packet and message
format as described in[I-D.ietf-manet-packetbb].
These fields are defined as follows: All DYMO messages are sent using UDP to the destination port TBD.
Route Node Address (Route.DestAddress) All DYMO messages are sent with the IP destination address set to the
link local multicast address LL_ALL_MANET_ROUTER unless otherwise
stated.
The IP address of the node associated with the routing table The IP TTL (IP Hop Limit) field for all DYMO messages is set to one
entry. (1).
Route Delete Timeout (Route.DeleteTimeout) The length of IP addresses (32-bits for IPv4 and 128-bits for IPv6)
inside DYMO messages are dependent on the IP packet header. 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, IPv4 addresses are carried in IPv6
as specified in [RFC3513].
If the time current is after Route.DeleteTimeout the 4.2.2. Routing Message (RM)
corresponding routing table entry MUST be deleted.
Route Hop Count (Route.HopCnt) Routing Messages (RM) are used to disseminate routing information.
There are two DYMO message types that are RM, RREQ and RREP. They
contain the same information, but have slightly different processing
rules. The fundamental difference between the two messages are that
RREQ messages require a response; while a RREP is the response to
RREQ.
The number of intermediate node hops before reaching the RM creation and processing are described in Section 5.3.
Route.DestAddress.
Route Is Gateway (Route.IsGateway) A RM requires the following information:
1-bit selector indicating whether the Route.DestAddress is a IP.DestinationAddress
gateway, see Section 4.8. The IP address of the packet destination.
Route Next Hop Address (Route.NextHopAddress) MsgHdr.HopLimit
The remaining number of hops this message may traverse.
The IP address of the next node on the path toward the AddBlk.Target.Address
Route.DestAddress. The IP address of the message target. In RREQ the target is the
unknown destination. In RREP the target is the RREQ originator.
Only one address can be marked as the target.
Route Next Hop Interface (Route.NextHopInterface) AddBlk.Orig.Address
The IP address of the message originator. This address is in an
address block and not in the message header to allow for address
compression and additional AddTLVs.
The interface used to send packets toward the AddTLV.Orig.SeqNum
Route.DestAddress. The DYMO sequence number of the message originator.
Route Prefix (Route.Prefix) A RM may optionally include the following information:
8-bit field that specifies the size of the subnet reachable AddTLV.Target.SeqNum
through the Route.DestAddress, see Section 4.7. The definition The last known DYMO sequence number of the target. If the
of the Prefix field is different for gateways; entries with AddTLV.Target.SeqNum is set to zero (0), then only the destination
Route.IsGateway set to one (1), see Section 4.8. may respond to this RREQ.
Route Sequence Number (Route.SeqNum) AddBlk.AdditionalNode.Address
The IP address of an additional node that can be reached via the
node adding this information. Each AdditionalNode.Address must
have an associated SeqNum in the message.
The sequence number of the Route.DestAddress, zero (0) if AddTLV.AdditionalNode.SeqNum
unknown. The DYMO sequence number of the additional node's routing
information.
Route.ValidTimeout AddTLV.Node.HopCnt
The number of IP hops to reach the associated Node.Address.
The time at which a route table entry is scheduled to be AddTLV.Node.Prefix
invalidated. The routing table entry is no longer considered The Node.Address is a network address ([I-D.ietf-manet-packetbb]).
valid if the current time is after Route.ValidTimeout.
3.2. DYMO Messages AddTLV.Node.IsGateway
This AddTLV indicates that the Internet is reachable via this
node. That is, all nodes outside this Node's prefix are reachable
via the advertising Node.
3.2.1. Generalized MANET Packet and Message Structure AddTLV.Node.IsTarget
If the target is not the first address in the address blocks, this
AddTLV is used to indicate the target.
All DYMO messages conform to the generalized packet and message AddTLV.Node.IsOriginator
format as described in [5]. In the event that the originator is not the second address in the
address blocks, this AddTLV is used to indicate the originator.
3.2.2. Routing Message (RM) AddTLV.AdditionalNode.IsOffPath
This AddTLV is used to indicate that a node is not on the path
between the originator and the target.
Routing messages are used to disseminate routing information. The AddTLV.Node.Ignore
two message types are RREQ and RREP and they have the same general If the information associated with this Node.Address should not be
format. RREQ messages require a response, while RREP are responses used create or update a route, this flag is set.
to RREQ.
Routing message creation and processing are described in Section 4.3. Not including this optional information may result in sub-optimal
performance, but it is not required for correct protocol operation.
Example Simple RREQ/RREP Routing Message Example IPv4 RREQ
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| msg-type | RSRV |U|N|0|1| msg-size | | IP.DestinationAddress=LL_ALL_MANET_ROUTERS |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| msg-ttl | msg-hopcnt | msg-tlv-block-size=0 | ...
UDP Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination Port=TBD |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
...
Message Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Head Length | Head |Number Tails=2 | | RREQ-type | Resv |0|0|1| msg-size=24 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TailOrig | TailTarget | tlv-block-size | | msg-hoplimit | msg-hopcnt | msg-tlv-block-size=0 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|DYMOSEQNUM-type| TLV Length | Orig.SeqNum.: ...
Address Block
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
:.Orig.SeqNum | Target.SeqNum | |Number Addrs=2 |0|HeadLength=24| Head :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: Head (cont) | Target.Tail | Orig.Tail | TLV-blk-size :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: size=7 (cont) |
+-+-+-+-+-+-+-+-+
...
Address TLVs
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|DYMOSeqNum-type| Resv |1|0|0|0| Index Start=1 | Index Stop=1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| tlv-length=16 | Orig.SeqNum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1 Figure 1
o RM conform to the generalized message format. 4.2.3. Route Error (RERR)
o msg-type = DYMO-RREQ or DYMO-RREP
o msg-semantics
* RM indicate inclusion of msg-ttl and msg-hop-count in msg-
header-info, by setting bit 1
o msg-header-info
* RM contains msg-ttl
* RM contains msg-hop-count
o add-block entries
* RM contain 1 and only 1 address marked as Originator - If no RERR are used to disseminate that a valid route is not available for
address is marked as the originator the first address is a particular destination, or set of destinations.
assumed to be the Originator
* if the RM is unicast (the IPDestinationAddress is a unicast RERR creation and processing are described in Section 5.5.3 and
address), RM contain 1 and only 1 address marked as Target Section 5.5.4.
(Target) - if no address is marked the second address is
assumed to be the Target
o add-tlv A RERR requires the following information:
* RM contain the DYMO Sequence Number of the Originator IP.DestinationAddress
(Orig.SeqNum) in a DYMO Sequence Number tlv The IP address of the packet destination.
* RM should contain the SeqNum for each address. If the SeqNum MsgHdr.HopLimit
is not included a value of Zero (0) is assumed. For the Target The remaining number of hops this message may traverse.
the SeqNum will be the Last Known SeqNum (Target.SeqNum) or
Zero (0) to indicate that only the Target can reply
* RM should contain the HopCnt for each address. If HopCnt is AddBlk.Unreachable.Address
not included, it is assumed to be zero (unknown). For the The IP address of an Unreachable Node. Multiple Unreachable
Target the HopCnt should be the Last Known HopCnt Addresses may be included. If a SeqNum for this address is not
(Target.HopCnt) included, it is assumed to be unknown.
* RM should contain a Prefix for each address that is not a host A Route Error may optionally include the following information:
address. If a prefix is not included in conjunction with an
address, it is assumed zero (host address only). For more
information on advertising a Prefix see Section 4.7.
* RM should contain a Gateway tlv for an address that is a AddTLV.Unreachable.SeqNum
gateway. If gateway indicator is not included in association The DYMO sequence number of the Unreachable Node.
with an address, the address is assumed to not be a gateway.
For more information on gateway operation see Section 4.8.
3.2.3. Route Error (RERR) AddTLV.Node.Ignore
If the information associated with Node.Address should not be used
to invalidate routes, this flag is set.
Example Simple RERR Message Example IPv4 RERR
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| rerr-msg-type | RSRV |U|N|0|1| msg-size | | IP.DestinationAddress=LL_ALL_MANET_ROUTERS |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| msg-ttl | msg-hopcnt | msg-tlv-block-size=0 | ...
UDP Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination Port=TBD |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
...
Message Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Head Length | Head |Number Tails=1 | | RERR-type | Resv |0|0|1| msg-size=16 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tail1 | tlv-block-size |dymo-seqnum-typ| | msg-hoplimit | msg-hopcnt | msg-tlv-block-size=0 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TLV Length | Tail1.SeqNum | ...
Address Block
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Number Addrs=1 |0|HeadLength=0 | Unreachable.Addr :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: Unreachable.Addr (cont) | TLV-blk-size=0 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2 Figure 2
o RERR conform to the generalized message format. 5. Detailed Operation
o msg-type = DYMO-RERR
o msg-semantics
* RERR indicates inclusion of msg-ttl and msg-hop-count in msg-
header-info, using bit 1
o msg-header-info
* RERR contain msg-ttl
* RERR contain msg-hop-count
o add-block entries
* All addresses are considered unreachable unless marked
otherwise
o add-tlvs
* RERR should contain SeqNum for each unreachable node. If the
SeqNum is not included in the message it is assumed to be zero
(unknown)
* RERR should contain the Last Known HopCnt for each unreachable
node. If the HopCnt is not included in the message it is
assumed to be zero (unknown)
4. Detailed Operation 5.1. DYMO Sequence Numbers
4.1. Sequence Numbers DYMO sequence numbers allow nodes to judge the freshness of routing
information, and ensure loop freedom.
4.1.1. Maintaining a Sequence Number 5.1.1. Maintaining A Node's Own Sequence Number
DYMO requires each node in the network to maintain its own DYMO DYMO requires a each node in the network to maintain its own DYMO
sequence number (OwnSeqNum), a 16-bit unsigned integer. The sequence number (OwnSeqNum), a 16-bit unsigned integer. The
circumstances for a node to change its OwnSeqNum are described in circumstances for a node to incrementing its OwnSeqNum are described
Section 4.3.1. in Section 5.3.
4.1.2. Incrementing a Sequence Number 5.1.2. Incrementing a Sequence Number
When a node increments its OwnSeqNum (as described in Section 4.3.1 When a node increments its OwnSeqNum (as described in Section 5.3) it
and Section 4.3.2) it MUST do so by treating the sequence number MUST do so by treating the sequence number value as if it was an
value as if it was an unsigned number. The sequence number zero (0) unsigned number. The sequence number zero (0) is reserved and is
is reserved and is used in several DYMO data structures to represent used in several DYMO data structures to represent an unknown sequence
an unknown sequence number. number.
4.1.3. Sequence Number Rollover 5.1.3. Sequence Number Rollover
If the sequence number has been assigned to be the largest possible If the sequence number has been assigned to be the largest possible
number representable as a 16-bit unsigned integer (i.e., 65535), then number representable as a 16-bit unsigned integer (i.e., 65535), then
the sequence number MUST be set to 256 when incremented. Setting the the sequence number MUST be set to 256 when incremented. Setting the
sequence number to 256 allows other nodes to detect that the number sequence number to 256 allows other nodes to detect that the number
has rolled over and the node has not lost its sequence number. has rolled over and the node has not lost its sequence number.
4.1.4. Actions After Sequence Number Loss 5.1.4. Actions After Sequence Number Loss
A node SHOULD maintain its sequence number in persistent storage. A node can maintain its sequence number in persistent storage,
between reboots.
If a node's OwnSeqNum is lost, it must take certain actions to avoid If a node's OwnSeqNum is lost, it must take certain actions to avoid
creating routing loops. To prevent this possibility after sequence creating routing loops. To prevent this possibility after OwnSeqNum
number loss a node MUST wait for at least ROUTE_DELETE_PERIOD before loss a node MUST wait for at least ROUTE_DELETE_PERIOD before fully
fully participating in the DYMO routing protocol. If a DYMO control participating in the DYMO routing protocol. If a DYMO control
message is received during this waiting period, the node SHOULD message is received during this waiting period, the node SHOULD
process it normally but MUST not transmit or retransmit any RM. If a process it normally but MUST not transmit or retransmit any DYMO
data packet is received for forwarding to another destination during messages. If a data packet is received for forwarding to another
this waiting period the node MUST generate a RERR message indicating destination during this waiting period, the node MUST generate a RERR
that this route is not available and reset its waiting period. RERR message indicating that this route is not available and reset its
generation is described in Section 4.5.3. At the end of the waiting waiting period. RERR generation is described in Section 5.5.3. At
period a node sets its sequence number to one (1). the end of the waiting period a node sets its OwnSeqNum to one (1).
4.2. DYMO Routing Table Operations 5.2. DYMO Routing Table Operations
4.2.1. Creating or Updating a Route Table Entry from Routing Message 5.2.1. Judging New Routing Information's Usefulness
Information
While processing a RM, as described in Section 4.3.2, a node checks
its routing table for an entry to the Node.Address using longest-
prefix matching [6]. In the event that no matching entry is found,
an entry is created.
If a matching entry is found, the routing information about Given a routing table entry (Route.SeqNum, Route.HopCnt, and
Node.Address contained in this RM is NOT stale if the result of Route.ValidTimeout) and new routing information for a particular node
subtracting the Route.SeqNum from Node.SeqNum is equal to zero (0) in a RM (Node.SeqNum, Node.HopCnt, and RM message type - RREQ/RREP),
using signed 16-bit arithmetic but it SHOULD be disregarded if: the quality of the new routing information is evaluated to determine
its usefulness. The following comparisons are performed in order:
o the Route.ValidTimeout has not passed and Node.HopCnt is greater 1. Stale
than or equal to Route.HopCnt, OR If Node.SeqNum - Route.SeqNum < 0 (using signed 16-bit arithmetic)
the information is stale. Using stale routing information is not
allowed, since doing so might result in routing loops.
o the Route.ValidTimeout has passed and Node.HopCnt is greater than 2. Loop-prone
Route.HopCnt plus one (1). If Node.SeqNum == Route.SeqNum the information maybe loop-prone,
additional information must be examined. If Route.HopCnt is
unknown or set to zero (0), then the routing information is loop-
prone. Likewise, if Node.HopCnt is unknown or set to zero (0),
then the routing information is loop-prone. If Node.HopCnt >
Route.HopCnt + 1, then the routing information is loop-prone.
Using loop-prone routing information is not allowed, since doing
so might result in routing loops.
If the information associated with this Node.Address is stale or 3. Inferior
disregarded and this Node.Address is the Originator then this DYMO If Node.SeqNum == Route.SeqNum the information may be inferior,
message MUST be dropped. For other Node.Addresses that are stale or additional information must be examined. If the route is valid
disregarded, the information is simply removed from the RM. Removing (by examining Route.ValidTimeout and the current time), then the
stale and disregarded routing informations ensures that unused new information is inferior if Node.HopCnt > Route.HopCnt. If the
information is not propagated further. route is valid, then the new information is also inferior if
Node.HopCnt == Route.HopCnt AND this RM is a RREQ.
If the route information for Node.Address is not stale or 4. Fresh
disregarded, then the following actions occur to the route table Routing information that does not match any of the above criteria
entry for Node.Address: is loop-free and better than the information existing in the
routing table. Only this type of information is used to update
the routing table.
1. the Route.HopCnt is set to the Node.HopCnt, 5.2.2. Updating a Route Table Entry with Fresh Routing Information
2. the Route.IsGateway is set to the G-bit, If fresh routing information is received, the routing 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,
3. the Route.NextHopAddress is set to the node that transmitted this 3. the Route.NextHopAddress is set to the node that transmitted this
DYMO packet (IPSourceAddress), DYMO packet (IP.SourceAddress),
4. the Route.NextHopInterface is set to the interface that this DYMO 4. the Route.NextHopInterface is set to the interface that this DYMO
packet was received on, packet was received on,
5. the Route.Prefix is set to Node.Prefix,, 5. the Route.ValidTimeout is set to the current time +
ROUTE_VALID_TIMEOUT,
6. the Route.SeqNum is set to the Node.SeqNum, 6. the Route.HopCnt is set to the Node.HopCnt,
7. and the Route.ValidTimeout is set to the current time + 7. the Route.Prefix is set to the Node.Prefix,
ROUTE_TIMEOUT.
8. the Route.IsInternetGateway is set if address is an Internet
Gateway.
Unknown values are set to zero (0).
If a valid route exists to Node.Address at this point, the route can If a valid route exists to Node.Address at this point, the route can
be used to send any queued data packets and to fulfill any be used to send any queued data packets and to fulfill any
outstanding route requests. outstanding RREQ.
4.2.2. Route Table Entry Timeouts 5.2.3. Route Table Entry Timeouts
Before using a routing table entry its timeouts must be examined.
If the current time is after Route.DeleteTimeout the corresponding If the current time is after Route.DeleteTimeout the corresponding
routing table entry MUST be deleted. routing table entry MUST be deleted.
If the current time is later than a routing entry's If the current time is later than a routing entry's
Route.ValidTimeout, the route is stale and it is not be used to route Route.ValidTimeout, the route is stale and cannot be used to route
packets. The information in invalid entries can still be used for packets. The information in invalid entries is still used for
filling fields in outgoing RM with last known values. filling fields in outgoing RM with last known values.
4.3. Routing Message 5.3. Routing Message
4.3.1. Routing Message Creation 5.3.1. RREQ Creation
When a node creates a RREQ it SHOULD increment its OwnSeqNum by one When a node creates a RREQ it SHOULD increment its OwnSeqNum by one
according to the rules specified in Section 4.1.2. When a node (1) according to the rules specified in (Section 5.1.2).
creates a RREP in response to a RREQ, it MUST increment its OwnSeqNum
under the following conditions:
o Target.SeqNum is greater than OwnSeqNum OR Fist, the node adds the AddBlk.Target.Address to the RM.
o Target.SeqNum is equal to OwnSeqNum AND Target.HopCnt is unknown If a previous value of the Target.SeqNum is known (from an existing
OR routing table entry), it SHOULD be placed in AddTLV.Target.SeqNum.
If a Target.SeqNum is not included, it is assumed to be unknown by
processing nodes and only the target is allowed to respond. A
Target.SeqNum of zero (0) MAY be set to indicate that any node with
valid routing information about this destination can respond to this
RREQ if the node is so enabled, though the process for doing so is
not described in this document.
o Target.SeqNum is equal to OwnSeqNum AND Orig.HopCnt is unknown OR Similarly, if a previous value of the Target.HopCnt is known, it
SHOULD be placed in AddTLV.Target.HopCnt. Otherwise, the HopCnt is
not included and assumed unknown by processing nodes.
o Target.SeqNum is equal to OwnSeqNum AND Target.HopCnt (the last These AddTLVs associated with the target SHOULD be set to maximum
know hop count value) is less than to Orig.HopCnt (the number of protocol efficiency, but they may be omitted to reduce message size.
hops traversed by this RREQ to reach the target).
In either case (both RREQ and RREP), the node MUST add the Next, the node adds AddBlk.Orig.Address to the RM and the
Orig.Address to the add-block and the Orig.SeqNum to the add-tlv- AddTLV.Orig.SeqNum (OwnSeqNum) in an address block TLV. The
block. It sets the Orig.Address to its own address. The Orig.SeqNum Orig.Address is this node's primary addresses/identifier. The
is the node's OwnSeqNum. The node MAY advertise a prefix using the Orig.Address must be a routable IP address.
Prefix add-tlv, as described in Section 4.7. Otherwise, the Prefix
add-tlv is not included. The node MAY advertise it is a gateway by
using a gateway add-tlv, as described in Section 4.8. Otherwise, the
gateway add-tlv is not included. The msg-ttl SHOULD be set to
NET_DIAMETER, but MAY be set smaller. The msg-hopcnt is set to zero
(0). the case of RREQ, the msg-ttl MAY be set in accordance with an
expanding ring search as described in [2] to limit the RREQ
propagation to a subset of the network and possibly reduce route
discovery overhead.
4.3.2. Routing Message Processing Other AddTLVs for the originator SHOULD be set to maximum protocol
efficiency, but they may be omitted to reduce message size.
After general message pre-processing (Section 4.6.2), a route to the The MsgHdr.HopCnt is set to zero (0). The MsgHdr.HopLimit SHOULD be
Originator is then created or updated, as described in Section 4.2.1. set to NET_DIAMETER, but MAY be set smaller. 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.
If a valid route to the Originator is not created or updated then the 5.3.2. RREP Creation
message MUST be dropped.
Each additional address in the address block(s) SHOULD be processed When a node creates a RREP in response to a RREQ, it MUST increment
except the Target. For each of these addresses the Node.HopCnt its OwnSeqNum under the following conditions:
associated with the address is incremented by one (1) if it exists
and is not zero, then a route is created or updated as defined in
Section 4.2.1. The updating of the HopCnt occurs after processing.
Each address resulting in a valid route entry may alleviate a future
route discovery. Any addresses that do not yield a valid route or
that are not processed MUST be removed from the RM. Only valid
routing information is propagated within RM messages.
If this node is the Target AND this is a RREQ, this node responds o Target.SeqNum is not included in the message, OR
with a RREP. The Target creates a new RREP as described in
Section 4.3.1. The Target.Address in the new RM is set to the
Orig.Address from the RM currently being processed. The
Target.HopCnt is the hop count for the Orig.Address. The
IPDestinationAddress is set to the Route.NextHopAddress for the
Orig.Address of the current RM being processed. The Target.SeqNum is
set to Route.SeqNum for Orig.Address from the current RM being
processed. Then the new RM undergoes post-processing, according to
Section 4.6.4.
After processing a RM, a node MAY append its routing information to o Target.SeqNum is zero (0), OR
the RM, according to the process described in Section 4.3.3. The
additional routing information will reduce route discoveries to this
node. If all nodes along the path append their information path
information will also be available.
If this node is not the Target.Address and this is a RREQ the current o Target.SeqNum - OwnSeqNum > 0 (using 16-bit signed arithmetic), OR
RM SHOULD be MANETcast. If this node is not the Target Address and
this is a RREP the current RM SHOULD be unicast to the next hop
address on the route to the Target.
If this node is the Target.Address, the current message is processed, o Target.SeqNum == OwnSeqNum AND Target.HopCnt is unknown, OR
but this message is not forwarded or retransmitted.
4.3.3. Appending Additional Routing Information to an Existing Routing o Target.SeqNum == OwnSeqNum AND Orig.HopCnt is unknown, OR
Message
o Target.SeqNum == OwnSeqNum AND Target.HopCnt (the last know hop
count value) < Orig.HopCnt (the number of hops traversed by this
RREQ to reach the target).
First, the node adds the AddBlk.Target.Address to the RM. The
Target.Address is copied from the incoming RREQ AddBlk.Orig.Address.
Next, the node adds the AddBlk.Orig.Address to the RM and the
AddTLV.Orig.SeqNum (OwnSeqNum) in an address block TLV. The
Orig.Address is copied from the incoming RREQ AddBlk.Target.Address.
Other AddTLVs for the originator and target SHOULD be set to maximum
protocol efficiency, but they may be omitted to reduce message size.
The MsgHdr.HopCnt is set to zero (0). The MsgHdr.HopLimit is set to
NET_DIAMETER.
5.3.3. RM Processing
When a RM is received the MsgHdr.HopLimit is decremented by one (1)
and MsgHdr.HopCnt is incremented by one (1).
For each address in the RM that includes AddTLV-HopCnt information
except the target and those addresses tagged with the AddTLV-Ignore,
the AddTLV-HopCnt information is incremented by one (1).
Next, this node checks whether its routing table has an entry to the
AddBlk.Orig.Address using longest-prefix matching [RFC1812]. If a
route does not exist, 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 routing table entry exists, the new node's
information is compared with the route table entry following the
procedure described in Section 5.2.1. If the new node's routing
information is considered fresh, the route table entry is updated as
described in Section 5.2.2.
If the routing information for the originator is not fresh then this
RM must be discarded and no further processing of this message is
performed.
If the originator's routing information was considered fresh, then
each address that is not the target and is not flagged with the
Ignore address-block-tlv SHOULD considered for creating and updating
routes. If routing table space is limited, only the routing
information about the originator is required. Creating and updating
routes for other locations can eliminate RREQ for those destination,
in the event that data needs to be forwarded to these destinations in
the near future.
For each of these addresses considered, if 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 routing
table entry exists, the new node's information is compared with the
route table entry following the procedure described in Section 5.2.1.
If the new node's routing information is considered fresh, the route
table entry is updated as described in Section 5.2.2.
If the routing information for an Node.Address is not considered
fresh, then if MUST be removed from the RM. Removing this
information ensures that non-fresh information is not propagated.
If this node is the target AND this RM is a RREQ, this node responds
with a RREP. This node creates a new RREP as described in
Section 5.3.2.
After processing a RM or creating a new RM, a node MAY append
additional routing information to the RM, according to the process
described in Section 5.3.4. The additional routing information will
help reduce route discoveries at the expense of increased message
size.
If this RM's MsgHdr.HopLimit is greater than one (1), this node is
not the target, AND this RM is a RREQ, then the current RM (altered
by the process defined above) SHOULD be sent to the
LL_ALL_MANET_ROUTERS IP.DestinationAddress.
If this RM's MsgHdr.HopLimit is greater than one (1), this node is
not the target, AND this RM is a RREP, then the new RM SHOULD be sent
to the Route.NextHopAddress for the RREP's Target.Address.
If this node is the target, the current RM's information is not
retransmitted.
5.3.4. Adding Additional Routing Information to a RM
Appending routing information will alleviate route discovery attempts Appending routing information will alleviate route discovery attempts
to this node from other nodes that process the resultant RM to the nodes whose information is included, if other nodes use this
information. Nodes MAY append a their routing information to a RM information to update their routing tables.
processed if they believe that this additional routing information
will alleviate future RREQ.
Prior to appending their address to a RM, a node MUST increment its Nodes MAY append routing information to a RM, if the node believe
OwnSeqNum as defined in Section 4.1.2. Then it appends its IP that this additional routing information will alleviate future RREQ.
address and OwnSeqNum. It MAY also append its Prefix and G-bit to This option should be administratively controlled.
the RM. This Node.HopCnt is set to one (1) if included. Several
length fields MUST also be adjusted to include the newly inserted
information.
4.4. Route Discovery Prior to appending their own address to a RM, a node MUST increment
its OwnSeqNum as defined in Section 5.1.2. Then the node appends its
IP address (AddBlk-Address) and OwnSeqNum (AddTLV-SeqNum). It MAY
also append other information to its address, such as prefix and/or
that it is an Internet Gateway. If included, the Node.HopCnt is set
to one (1).
A node generates a Route Request (RREQ) to discover a route to a Routing information about other nodes MAY also be added. If this
particular destination (Target). If a sequence number is known for information is included, it must be flagged with the
the Target it is placed in the RREQ. Otherwise, Target.SeqNum AddTLV.AdditionalNode.IsOffPath.
assumed to be unknown by processing nodes. A Target.SeqNum of zero
(0) MAY be set to indicate that only the destination may respond to Note an address may appear only once in a message's address blocks.
this RREQ. If a previous value of the HopCnt is known for the Target Prior to adding any address, the message is searched for existing
it is placed in a corresponding add-tlv HopCnt. Otherwise, the entries. If an existing entry exists, this entry will have the
HopCnt is not included. The IPDestinationAddress is set to the information as this node's routing table information (created or
MANETcastAddress. Then the RM is transmitted according to the updated while processing the RM) and therefore no update is
procedure defined in Section 4.6.5. necessary.
In the event a newly appended address already has an AddTLV-Ignore
flag set, it is removed.
5.4. Route Discovery
A node creates a RREQ (described in Section 5.3.1) to discover a
route to a particular destination (target). The
IP.DestinationAddress for this RREQ is set to the
LL_ALL_MANET_ROUTERS. Then the RM is transmitted.
After issuing a RREQ, the originating node waits for a route to be After issuing a RREQ, the originating node waits for a route to be
created to the Target. If a route is not found within RREQ_WAIT_TIME created to the target. If a route is not found within RREQ_WAIT_TIME
milliseconds, this node MAY again try to discover a route by issuing milliseconds, this node MAY again try to discover a route by issuing
another RREQ. another RREQ.
To reduce congestion in a network, repeated attempts at route To reduce congestion in a network, repeated attempts at route
discovery for a particular Target SHOULD utilize a binary exponential discovery for a particular target SHOULD utilize a binary exponential
backoff. The first time a node issues a RREQ, it waits backoff. The first time a node issues a RREQ, it waits
RREQ_WAIT_TIME milliseconds for a route to the Target. If a route is RREQ_WAIT_TIME milliseconds for a route to the target. If a route is
not found within that time, the node MAY send another RREQ. If a not found within that time, the node MAY send another RREQ. If a
route is not found within two (2) times the current waiting time, 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 another RREQ may be sent, up to a total of RREQ_TRIES. For each
additional attempt, the waiting time for the previous RREQ is additional attempt, the waiting time for the previous RREQ is
multiplied by two (2) so that the waiting time conforms to a binary multiplied by two (2) so that the waiting time conforms to a binary
exponential backoff. exponential backoff.
Data packets awaiting a route SHOULD be buffered. Data packets awaiting a route SHOULD be buffered. This buffer SHOULD
have a fixed limited size and discard older data packets first.
If a route discovery has been attempted RREQ_TRIES times without If a route discovery has been attempted RREQ_TRIES times without
receiving a route to the Target, all data packets destined for the receiving a route to the target, all data packets destined for the
corresponding Target SHOULD be dropped from the buffer and a corresponding target are dropped from the buffer and a Destination
Destination Unreachable ICMP message SHOULD be delivered to the Unreachable ICMP message SHOULD be delivered to the application.
application.
4.5. Route Maintenance
4.5.1. Active Link Monitoring 5.5. Route Maintenance
Before a route can be used for forwarding a packet, it MUST be A RERR MUST be issued if a data packet is received and it cannot be
checked to make sure that the route is still valid. If the delivered to the next hop, RERR generation is described in
Route.ValidTimeout is earlier than the current time, the packet Section 5.5.3. A RERR MAY be issued immediately after detecting a
cannot be forwarded, and a RERR message MUST be generated (see broken link of an active route to quickly notify nodes that a link
section Section 4.5.3). In this case, the Route.DeleteTimeout is set break occurred and certain routes are no longer available. If a
to Route.ValidTimeout + ROUTE_DELETE_TIMEOUT. route has not been used, a RERR SHOULD NOT be generated unless
generation is expected to reduce future traffic.
If the current time is after Route.DeleteTimeout, then the route MUST 5.5.1. Active Link Monitoring
be deleted, though a route MAY be deleted at any time.
Nodes MUST monitor links on active routes. This may be accomplished Nodes MUST monitor links on active routes that are being used. This
by one or several mechanisms. Including: may be accomplished by one or several mechanisms. Including:
o Link layer feedback o Link layer feedback
o Hello messages o Neighborhood discovery [I-D.ietf-manet-nhdp]
o Neighbor discovery
o Route timeout o Route timeout
o Other monitoring mechanisms or heuristics o Other monitoring mechanisms or heuristics
Upon detecting a link break the detecting node MUST set the Upon detecting a link break the detecting node MUST set the
Route.ValidTimeout to the current time for all active routes Route.ValidTimeout to the current time for all active routes
utilizing the broken link. utilizing the broken link.
A RERR MUST be issued if a data packet is received and it cannot be 5.5.2. Updating Route Lifetimes during Packet Forwarding
delivered to the next hop. RERR generation is described in
Section 4.5.3. A RERR MAY be issued after detecting a broken link of
an active route to quickly notify nodes that a link break occurred
and a route or routes are no longer available. If a route has not
been used, a RERR SHOULD NOT be generated unless generation is
expected to reduce future control traffic.
4.5.2. Updating Route Lifetimes
To avoid route timeouts for active routes, a node MUST update the To avoid route timeouts for active routes, a node SHOULD update the
Route.ValidTimeout to the IPSourceAddress to be the current time + Route.ValidTimeout for the IP.SourceAddress to be the current time +
ROUTE_TIMEOUT upon receiving a data packet. ROUTE_VALID_TIMEOUT upon receiving a data packet. This route's
Route.Used bit is also set, if implemented.
To avoid route timeouts for active routes, a node SHOULD update the To avoid route timeouts for active routes, a node SHOULD update the
Route.ValidTimeout to the IPDestinationAddress to be the current time Route.ValidTimeout for the IP.DestinationAddress to be the current
+ ROUTE_TIMEOUT upon successfully transmitting a packet to the next time + ROUTE_VALID_TIMEOUT upon successfully transmitting a packet to
hop. the next hop. This route's Route.Used bit is also set.
4.5.3. Route Error Generation 5.5.3. Route Error Generation
When a data packet is received for a destination without a valid When a data packet is received for a destination without a valid
routing table entry, a Route Error (RERR) MUST be generated by this routing table entry, a RERR MUST be generated. When a RREP is being
node. A RERR informs the source that the route does not exist, is no transmitted and no active route to the target exists, a RERR MUST be
longer available, or is now invalid. generated. A RERR informs the IP.SourceAddress that the route does
not exist, is no longer available, or is now invalid.
In a new RERR, the address of unreachable node (IPDestinationAddress) In a new RERR, the address of first unreachable node
from the data packet is inserted. If a value for the unreachable (IP.DestinationAddress from the data packet) is inserted. If a value
node's SeqNum is known, it is placed in the RERR; otherwise, if for the unreachable node's SeqNum (AddTLV-SeqNum) is known, it SHOULD
unknown it will be assumed to be zero (0). The msg-ttl SHOULD be set be placed in the RERR. The MsgHdr.HopLimit is set to NET_DIAMETER.
to NET_DIAMETER, but may be set smaller to limit the scope of the The MsgHdr.HopCnt is set to one (1).
RERR. The msg-hopcnt is set to zero (0). The IPDestinationAddress
is set to the MANETcastAddress. This option will notify the maximum
number of nodes of the broken link.
Additional unreachable nodes that required the same unavailable link Additional unreachable nodes that required the same unavailable link
(routes with the same Route.NextHopAddress and (routes with the same Route.NextHopAddress and
Route.NextHopInterface) MAY be added to the RERR. For each Route.NextHopInterface) MAY be added to the RERR. The SeqNum if know
unreachable node the Address is appended. The SeqNum if know should SHOULD also be included. Appending unreachable node information
also be included. Appending additional routing information notifies notifies each processing node of additional routes that are no longer
each processing node of additional routes that are no longer
available. available.
The RERR is then processed as described in Section 4.6.5. If SeqNum information is not known or not included all nodes
processing the routing information will assume their routing
4.5.4. Route Error Processing information associated with the unreachable node is no longer valid.
When a node processes a RERR, it SHOULD set the Route.ValidTimeout to The RERR is sent to the IP.DestinationAddress LL_ALL_MANET_ROUTERS.
the current time for each Address that meets all of the following Sending the RERR to the LL_ALL_MANET_ROUTERS address notifies the
conditions: maximum number of nodes of the broken link.
1. The Route.NextHopAddress is the same as the RERR IPSourceAddress. The packet or message that forced generation of this RERR is
discarded.
2. The Route.NextHopInterface is the same as the interface on which 5.5.4. Route Error Processing
the RERR was received.
3. The Node.SeqNum is zero (0), unknown, OR the result of When a node processes a RERR, it processes each unreachable node
subtracting Route.SeqNum from Node.SeqNum is less than or equal address. It sets the Route.ValidTimeout to the current time for each
to zero using signed 16-bit arithmetic. Address found using longest prefix matching that meet all of the
following conditions:
Each Node.Address that did not result in a change to 1. The Route.NextHopAddress is the same as the RERR
Route.ValidTimeout SHOULD be removed from the RERR, since propagation IP.SourceAddress.
of this information should not result in any benefit.
Prior to post processing a node MAY remove any unreachable node 2. The Route.NextHopInterface is the same as the interface on which
address and its associated information to decrease the message size. the RERR was received.
If this node is the Target and the IPDestinationAddress is its own 3. The Route.SeqNum is zero (0), unknown, OR the Node.SeqNum is zero
Address then it may stop processing. (0), unknown, OR Node.SeqNum - Route.SeqNum <= 0 (using signed
16-bit arithmetic).
If at least one unreachable node address remains in the RERR it Each unreachable node that did not result in a change to
SHOULD be handled as described in Section 4.6.4 to continue Route.ValidTimeout is removed from the RERR, since propagation of
notification of nodes effected by the broken link. Otherwise, the this information will not result in any benefit. Any information
RERR is dropped. associated with the removed addresses is also removed.
4.6. General DYMO Packet and Message Processing If no unreachable node addresses remain, no further processing is
performed.
4.6.1. Packet Processing If this RERR's MsgHdr.HopLimit is greater than one (1) and at least
one unreachable node address remains in the RERR, then the RERR is
sent to the IP.DestinationAddress LL_ALL_MANET_ROUTERS.
The length of IP addresses (32-bits for IPv4 and 128-bits for IPv6) Addresses marked with AddTLV-Ignore should remain in the RERR.
inside DYMO messages are dependent on the IP packet header. For
example, if the IP header uses IPv6 addresses then all messages and
addresses contained in the payload use IPv6 addresses.
4.6.2. Generic Message Pre-processing 5.6. General DYMO Packet and Message Processing
Each message undergoes pre-processing before the message specific 5.6.1. Receiving Packets
processing occurs. During pre-processing, the msg-ttl is decremented
by one (1) and the msg-hopcnt is incremented by one (1).
4.6.3. Processing Unknown Message and TLV Types When a packet is received, its PktTLV are first examined. Next each
message is examined and processed in order.
We expect the next version of the generalized MANET packet and Each message's headers are first examined. Next, the MsgTLV are
message format [5] to include message semantic bits and tlv semantic examined. Finally, each message is processed according to its
bits to control the behavior of unknown types. MsgHdr.type.
4.6.4. Generic Message Post-processing 5.6.2. Processing Unknown Message and TLV Types
If the msg-ttl of any message is zero (0) after processing it MUST be To allow future extensions, DYMO uses bits from the semantics fields
dropped. of PktTLV, Message, MsgTLV, and AddTLV [I-D.ietf-manet-packetbb].
Note [I-D.ietf-manet-packetbb] does not currently support this
functionality.
4.6.5. DYMO Control Packet Transmission The semantic bits have the following names and characteristics for
nodes that do not understand the type.
Packet transmission and re-transmission are controlled by the Remove
IPDestinationAddress. If the IPDestinationAddress is a unicast If the Semantics.Remove-bit is set, this information SHOULD be
address, the packet IPDestinationAddress is replaced by the removed from the message.
Route.NextHopAddress from a route table lookup for the Target. If a
route for the Target is unknown or invalid the packet is dropped and
a RERR SHOULD be generated.
For all currently defined DYMO packets the IPTTL (IPMaxCount) SHOULD Discard
be set to 1 (IPTTL=1), since all DYMO packet communications are If the Semantics.Discard-bit is set, this message SHOULD not be
exchanged between direct neighbors only. processed further and it should not be propagated. In the case of
PktTLVs if the Semantics.Discard-bit is set, no messages from the
packet should be processed or propagated.
4.7. Routing Prefix 5.7. Network Addresses
Any node MAY advertise connectivity to a subset of node addresses Any node MAY advertise a network address by using a Prefix tlv
within its address space by using a Prefix tlv [5]. The nodes (other [I-D.ietf-manet-packetbb]. Any nodes (other than the advertising
than the advertising node) within the advertised Prefix SHOULD NOT node) within the advertised Prefix SHOULD NOT participate in the
participate in the MANET and MUST be reachable by forwarding packets MANET and these nodes MUST be reachable by forwarding packets to the
to the node advertising connectivity. For example, 192.168.1.1 with node advertising connectivity. For example, A.B.C.1 with a prefix
a prefix of 16 indicates all nodes with the prefix 192.168.X.X are length of 24 indicates all nodes with the matching A.B.C.X are
reachable through 192.168.1.1. reachable through the node with address A.B.C.1.
The meaning of the Prefix field is altered for routes to the gateway; The meaning of the Prefix field is altered for theroute to an
Route.IsGateway is one (1). If the G-bit is set the Prefix in Internet gateway; Route.IsInternetGateway is one (1). If the route
association with the IP address indicates that all nodes outside the refers to an Internet gateway, its Prefix in association with the IP
subnet are reachable via the gateway node. For example, a route to a address indicates that all nodes outside that subnet are reachable
gateway with IP address 192.168.1.1 and a prefix of 16 indicates that via the Internet gateway node. For example, a route to a Internet
all nodes with an IP address NOT matching 192.168.X.X are reachable gateway with IP address A.B.C.1 and a prefix of 24 indicates that all
via this node. nodes with an IP address NOT matching A.B.C.X are reachable via this
node.
4.8. Simple Internet Attachment and Gatewaying 5.8. Simple Internet Attachment and Gatewaying
Simple Internet attachment consists of a network of MANET nodes Simple Internet attachment consists of a network of MANET nodes
connected to the Internet via a single gateway node. The gateway is connected to the Internet via a single Internet gateway node. The
responsible for responding to RREQs for Targets outside its gateway is responsible for responding to RREQs for targets outside
configured MANET subnet, as well as delivering packets to its configured MANET subnet, as well as delivering packets to
destinations outside the MANET. destinations outside the MANET.
/--------------------------\
/ Internet \
\ /
\------------+-------------/
MANET Subnet | A.B.C.X
+-----+-----+
| MANET |
/------| Internet |------\
/ | Gateway | \
/ | A.B.C.1 | \
| +-----------+ |
| MANET |
| |
| +------------+ |
| | MANET Node | |
| | A.B.C.2 | |
| +------------+ |
| +------------+ |
| | MANET Node | |
| | A.B.C.3 | |
\ +------------+ /
\ /
\-------------------------/
Figure 3: Simple Internet Attachament Example
MANET nodes wishing to be reachable from nodes in the Internet MUST MANET nodes wishing to be reachable from nodes in the Internet MUST
have IP addresses within the gateway's configured and advertised have IP addresses within the gateway's configured and advertised
MANET subnet. Given a node with a globally routeable address or MANET subnet. Given a node with a globally routeable address or
care-of address handled by the gateway, the gateway is responsible care-of address handled by the gateway, the gateway is responsible
for routing and forwarding packets received from the Internet for routing and forwarding packets received from the Internet
destined for nodes inside its MANET subnet. destined for nodes inside its MANET subnet.
Since many nodes may commonly wish to communicate with the gateway, Since many nodes may commonly wish to communicate with the gateway,
the gateway SHOULD indicate to nodes that it is a gateway by using the gateway SHOULD indicate to nodes that it is a gateway by using
the gateway tlv in any RM created or processed. The gateway tlv the gateway tlv in any RM transmitted. The Internet Gateway tlv
indicates to nodes in the MANET that the Node.Address is attached to indicates to nodes in the MANET that the Node.Address is attached to
the Internet and is capable of routing data packets to all nodes the Internet and is capable of routing data packets to all nodes
outside of the configured MANET subnet, defined by the Node.Address outside of the configured MANET subnet, defined by the Node.Address
and Node.Prefix fields. and Node.Prefix fields.
4.9. Multiple Interfaces 5.9. Multiple Interfaces
It is likely that DYMO will be used with multiple wireless It is likely that DYMO will be used with multiple wireless
interfaces; therefore, the particular interface over which packets interfaces; therefore, the particular interface over which packets
arrive must be known whenever a packet is received. Whenever a new arrive must be known whenever a packet is received. Whenever a new
route is created, the interface through which the Route.Address can route is created, the interface through which the Route.Address can
be reached is also recorded in the route table entry. be reached is also recorded in the route table entry.
When multiple interfaces are available, a node transmitting a When multiple interfaces are available, a node transmitting a packet
MANETcast packet SHOULD send the packet on all interfaces that have with IP.DestinationAddress set to LL_ALL_MANET_ROUTERS SHOULD send
been configured for DYMO operation. the packet on all interfaces that have been configured for DYMO
operation.
4.10. Packet Generation Limits 5.10. Packet Generation Limits
To avoid congestion, a node SHOULD NOT transmit more than RATE_LIMIT To avoid congestion, a node SHOULD NOT transmit more than RATE_LIMIT
control messages per second. RREQ packets SHOULD be discarded before control messages per second. RREQ packets SHOULD be discarded before
RREP or RERR packets. RREP or RERR packets.
5. Configuration Parameters 6. Configuration Parameters
Here are some default parameter values for DYMO:
Parameter Name Suggested Value
--------------------------- ---------------
NET_DIAMETER 10
RATE_LIMIT 10
ROUTE_TIMEOUT 5000 milliseconds
ROUTE_DELETE_TIMEOUT 5*ROUTE_TIMEOUT Suggested Parameter Values
RREQ_WAIT_TIME 1000 milliseconds +------------------------+-------------------------+
| Name | Value |
+------------------------+-------------------------+
| NET_DIAMETER | 10 |
| RATE_LIMIT | 10 |
| ROUTE_VALID_TIMEOUT | 5000 milliseconds |
| ROUTE_DELETE_TIMEOUT | 5 * ROUTE_VALID_TIMEOUT |
| ROUTE_DELETE_PERIOD | 6 * ROUTE_VALID_TIMEOUT |
| ROUTE_RREQ_WAIT_TIME | 1000 milliseconds |
| RREQ_TRIES | 3 |
+------------------------+-------------------------+
RREQ_TRIES 3 Table 1
For large networks or networks with frequent topology changes the These suggested values work well for small and medium well connected
default DYMO parameters should be adjusted using either networks with infrequence topology changes. For larger networks or
experimentally determined values or dynamic adaptation. For example, networks with frequent topology changes the default DYMO parameters
in networks with infrequent topology changes ROUTE_TIMEOUT may be set should be adjusted using either experimentally determined values or
to a much larger value. dynamic adaptation. For example, in networks with infrequent
topology changes ROUTE_VALID_TIMEOUT may be set to a much larger
value.
It is assumed that all nodes in the network share the same parameter It is assumed that all nodes in the network share the same parameter
settings. Different parameter values for ROUTE_TIMEOUT or settings. Different parameter values for ROUTE_VALID_TIMEOUT or
ROUTE_DELETE_TIMEOUT in addition to arbitrary packet delays may ROUTE_DELETE_TIMEOUT in addition to arbitrary packet delays may
result in frequent route breaks or routing loops. result in frequent route breaks or in extreme cases routing loops.
6. IANA Considerations 7. IANA Considerations
DYMO defines several message-types and tlv-types. A new registry DYMO requires a UDP port number to carry protocol packets - TBD.
will be created for the values for the various type fields, and the DYMO also requires the link-local multicast address
following values will be assigned: LL_ALL_MANET_ROUTERS; IPv4 TBD, IPv6 TBD.
msg-type Value This section also specifies several messages types, message tlv-
types, and address tlv-types.
-------------------------------- ------- Future types will be allocated using standard actions as described in
[RFC2434].
Route Request (DYMO-RREQ) 8 - TBD 7.1. DYMO Message Type Specification
Route Reply (DYMO-RREP) 9 - TBD The following address block TLV.
Route Error (DYMO-RERR) 10 - TBD DYMO Message Types
address-tlv Value +------------------------+----------+
| Name | Type |
+------------------------+----------+
| Route Request (RREQ) | 10 - TBD |
| Route Reply (RREP) | 11 - TBD |
| Route Error (RERR) | 12 - TBD |
+------------------------+----------+
-------------------------------- ----- Table 2
DYMO SeqNum (multivalue) 20 - TBD 7.2. Packet TLV Type Specification
HopCnt (multivalue) 21 - TBD Packet TLV Types
Prefix (multivalue) 0 [5] +-------------------+------+--------+-------------------------------+
| Name | Type | Length | Value |
+-------------------+------+--------+-------------------------------+
| Unicast Response | TBD | 10 - | Indicates to the processing |
| Request | | TBD | 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 |
| | | | the link is unidirectional |
| | | | and may blacklist this node. |
+-------------------+------+--------+-------------------------------+
Gateway (zero length) 22 - TBD Table 3
Originator 23 - TBD 7.3. Address Block TLV Specification
Target 24 - TBD Address Block TLV Specification Overview
Future values of the Type will be allocated using standard actions as +----------------------+------+--------+----------------------------+
described in [1]. For future Types that are unicast hop-by-hop | Name | Type | Length | Value |
(packets not sent to the MANETcastAddress), these Types MUST include +----------------------+------+--------+----------------------------+
the Target.Address field. | DYMOSeqNum | 10 - | 16 | The DYMO sequence num |
| | TBD | bits | associated with this |
| | | | address. The sequence |
| | | | number may be the last |
| | | | known sequence number. |
| HopCount | 11 - | 8 bits | The number of hops |
| | TBD | | traversed by the |
| | | | information associated |
| | | | with this address. |
| IsInternetGateway | 12 - | 0 bits | Usde to indicate that this |
| | TBD | | node is an Internet |
| | | | Gateway |
| IsOriginator | 13 - | 0 bits | Used to indicate that this |
| | TBD | | node is the Originator of |
| | | | the RM. |
| IsTarget | 14 - | 0 bits | Used to indicate this node |
| | TBD | | is the target of the DYMO |
| | | | message |
| Ignore | 15 - | 0 | Used to indicate that this |
| | TBD | | addresses should not be |
| | | | processed normally; |
| | | | instead it should be |
| | | | ignored. |
+----------------------+------+--------+----------------------------+
7. Security Considerations Table 4
8. Security Considerations
Currently, DYMO does not specify any special security measures. Currently, DYMO does not specify any special security measures.
Routing protocols, however, are prime targets for impersonation Routing protocols, however, are prime targets for impersonation
attacks. In networks where the node membership is not known, it is attacks. In networks where the node membership is not known, it is
difficult to determine the occurrence of impersonation attacks, and difficult to determine the occurrence of impersonation attacks, and
security prevention techniques are difficult at best. However, when security prevention techniques are difficult at best. However, when
the network membership is known and there is a danger of such the network membership is known and there is a danger of such
attacks, DYMO messages must be protected by the use of authentication attacks, DYMO messages must be protected by the use of authentication
techniques, such as those involving generation of unforgeable and techniques, such as those involving generation of unforgeable and
cryptographically strong message digests or digital signatures. cryptographically strong message digests or digital signatures.
skipping to change at page 27, line 5 skipping to change at page 27, line 22
dangerous, SHOULD be authenticated in order to prevent malicious dangerous, SHOULD be authenticated in order to prevent malicious
nodes from disrupting active routes between communicating nodes. nodes from disrupting active routes between communicating nodes.
If the mobile nodes in the ad hoc network have pre-established If the mobile nodes in the ad hoc network have pre-established
security associations, the purposes for which the security security associations, the purposes for which the security
associations are created should include that of authorizing the associations are created should include that of authorizing the
processing of DYMO control packets. Given this understanding, the processing of DYMO control packets. Given this understanding, the
mobile nodes should be able to use the same authentication mechanisms mobile nodes should be able to use the same authentication mechanisms
based on their IP addresses as they would have used otherwise. based on their IP addresses as they would have used otherwise.
8. Acknowledgments 9. Acknowledgments
DYMO is a descendant of the design of previous MANET reactive DYMO is a descendant of the design of previous MANET reactive
protocols, especially AODV [2] and DSR [4]. Changes to previous protocols, especially AODV [RFC3561] and DSR [Johnson96]. Changes to
MANET reactive protocols stem from research and implementation previous MANET reactive protocols stem from research and
experiences. Thanks to Elizabeth Belding-Royer for her long time implementation experiences. Thanks to Elizabeth Belding-Royer for
authorship of DYMO. Additional thanks to Luke Klein-Berndt, Pedro her long time authorship of DYMO. Additional thanks to Luke Klein-
Ruiz, Fransisco Ros and Koojana Kuladinithi for reviewing of DYMO, as Berndt, Pedro Ruiz, Fransisco Ros, Koojana Kuladinithi, Ramon
well as several specification suggestions. Caceres, and Thomas Clausen for reviewing of DYMO, as well as several
specification suggestions.
9. References 10. References
9.1. Normative References 10.1. Normative References
[1] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA [RFC1812] Baker, F., "Requirements for IP Version 4 Routers",
Considerations Section in RFCs", RFC 2434, BCP 26, October 1998. RFC 1812, June 1995.
[2] Perkins, C., Belding-Royer, E., and S. Das, "Ad hoc On-demand [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Distance Vector (AODV) Routing", RFC 3561, July 2003. Requirement Levels", BCP 14, RFC 2119, March 1997.
[6] Baker, R., "Requirements for IP Version 4 Routers", RFC 1812, [RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an
June 1995. IANA Considerations Section in RFCs", BCP 26, RFC 2434,
October 1998.
9.2. Informative References [RFC3513] Hinden, R. and S. Deering, "Internet Protocol Version 6
(IPv6) Addressing Architecture", RFC 3513, April 2003.
[3] Perkins, C. and E. Belding-Royer, "Ad hoc On-Demand Distance [RFC3561] Perkins, C., Belding-Royer, E., and S. Das, "Ad hoc On-
Vector (AODV) Routing", Proceedings of the 2nd IEEE Workshop on Demand Distance Vector (AODV) Routing", RFC 3561,
Mobile Computing Systems and Applications, New Orleans, LA, pp. July 2003.
90-100, February 1999.
[4] Johnson, D. and D. Maltz, "Dynamic Source Routing (DSR) in Ad 10.2. Informative References
hoc Networks", In Mobile Computing, Chapter 5, pp. 153-181,
1996.
[5] Clausen, T., Dearlove, C., and J. Dean, "Generalized MANET [I-D.ietf-manet-nhdp]
Packet/Message Format", February 2006. Clausen, T., Dearlove, C., and J. Dean, "MANET
Neighborhood Discovery Protocol", draft-ietf-manet-nhdp-00
(work in progress), June 2006.
[I-D.ietf-manet-packetbb]
Clausen, T., Dearlove, C., Dean, J., and C. Adjih,
"Generalized MANET Packet/Message Format",
draft-ietf-manet-packetbb-01 (work in progress),
June 2006.
[Johnson96]
Johnson, D. and D. Maltz, "Dynamic Source Routing (DSR) in
Ad hoc Networks", In Mobile Computing, Chapter 5, pp. 153-
181, 1996.
[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.
Authors' Addresses Authors' Addresses
Ian Chakeres Ian Chakeres
Boeing Phantom Works Boeing Phantom Works
The Boeing Company The Boeing Company
P.O. Box 3707 Mailcode 7L-49 P.O. Box 3707 Mailcode 7L-49
Seattle, WA 98124-2207 Seattle, WA 98124-2207
USA USA
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