draft-ietf-ospf-cap-03.txt   draft-ietf-ospf-cap-04.txt 
Network Working Group A. Lindem (Editor)
Network Working Group Acee Lindem Internet-Draft Cisco Systems, Inc
Internet Draft Naiming Shen Expires: May 30, 2005 N. Shen
Expiration Date: February 2005 Redback Networks BCN Networks, Inc
Rahul Aggarwal R. Aggarwal
Juniper Networks Juniper Networks
Scott Shaffer S. Schaffer
Level 3 Communications BridgePort Networks
JP Vasseur JP. Vasseur
Cisco Systems, Inc Cisco Systems, Inc
November 29, 2004
Extensions to OSPF for Advertising Optional Router Capabilities Extensions to OSPF for Advertising Optional Router Capabilities
draft-ietf-ospf-cap-03.txt draft-ietf-ospf-cap-04.txt
Status of this Memo Status of this Memo
By submitting this Internet-Draft, I certify that any applicable This document is an Internet-Draft and is subject to all provisions
patent or IPR claims of which I am aware have been disclosed, and of section 3 of RFC 3667. By submitting this Internet-Draft, each
any of which I become aware will be disclosed, in accordance with 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 become aware will be disclosed, in accordance with
RFC 3668. RFC 3668.
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Abstract This Internet-Draft will expire on May 30, 2005.
Copyright Notice
Copyright (C) The Internet Society (2004).
Abstract
It is useful for routers in an OSPF routing domain to know the It is useful for routers in an OSPF routing domain to know the
capabilities of their neighbors and other routers in the OSPF capabilities of their neighbors and other routers in the OSPF routing
routing domain. This draft proposes extensions to OSPF for domain. This draft proposes extensions to OSPF for advertising
advertising optional router capabilities. A new Router optional router capabilities. A new Router Information (RI) opaque
Information (RI) opaque LSA is proposed for this purpose. LSA is proposed for this purpose.
Conventions used in this document Table of Contents
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in 2. OSPF Router Information (RI) Opaque LSA . . . . . . . . . . . 4
this document are to be interpreted as described in RFC-2119 [3]. 2.1 OSPF Router Capabilities TLV . . . . . . . . . . . . . . . 5
2.2 Reserved OSPF Router Capability Bits . . . . . . . . . . . 6
2.3 Flooding Scope of the Router Information LSA . . . . . . . 6
3. Security Considerations . . . . . . . . . . . . . . . . . . . 8
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
5. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.1 Normative References . . . . . . . . . . . . . . . . . . . . 10
5.2 Informative References . . . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 10
A. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 12
Intellectual Property and Copyright Statements . . . . . . . . 13
1. Motivation 1. Introduction
It is useful for routers in an OSPF routing domain to know the It is useful for routers in an OSPF routing domain to know the
capabilities of their neighbors and other routers in the OSPF capabilities of their neighbors and other routers in the OSPF routing
routing domain. This can be useful for various applications: domain. This can be useful for various applications:
o In MPLS Traffic Engineering (TE), it can be used as a discovery o In MPLS Traffic Engineering (TE), it can be used as a discovery
mechanism [7, 8] to announce a LSR's TE capabilities like mechanism [TECAP] to announce a LSR's TE capabilities like Path
Path Computation Server capability (Capability of an LSR to be Computation Server capability (Capability of an LSR to be a Path
a Path Computation Server for TE LSP path computation) or the Computation Server for TE LSP path computation) or the intention
intention of an LSR to be part of a particular MPLS TE mesh group. of an LSR to be part of a particular MPLS TE mesh group.
o For network management and troubleshooting. It gives operators a o For network management and troubleshooting. It gives operators a
network wide view of OSPF capabilities on different routers. network wide view of OSPF capabilities on different routers. The
The presence of a capability on a given router implies presence of a capability on a given router implies that the
that the software version supports the capability and the router software version supports the capability and the router is
is configured to support it. On the other hand, the absence of an configured to support it. On the other hand, the absence of an
expected capability on a particular router can imply either expected capability on a particular router can imply either
misconfiguration or an incorrect software version. Hence, this misconfiguration or an incorrect software version. Hence, this
capability information can be used to track problems resulting from capability information can be used to track problems resulting
misconfiguration or an incorrect software version. from misconfiguration or an incorrect software version.
OSPF uses the options field in the hello packet to advertise optional OSPF uses the options field in the hello packet to advertise optional
router capabilities [1]. However, all the bits in this field have router capabilities [OSPF]. However, all the bits in this field have
been allocated and there is no way to advertise new optional been allocated and there is no way to advertise new optional or MPLS
or MPLS TE capabilities. This document proposes extensions to OSPF TE capabilities. This document proposes extensions to OSPF to
to advertise these optional capabilities. For existing OSPF advertise these optional capabilities. For existing OSPF
capabilities, this advertisement will be used primarily for capabilities, this advertisement will be used primarily for
informational purposes. For MPLS TE features, it is used for informational purposes. For MPLS TE features, it is used for
advertisement and discovery. Future OSPF features could also advertisement and discovery. Future OSPF features could also use
use this mechanism for advertisement and discovery. this mechanism for advertisement and discovery.
2. OSPF Router Information (RI) Opaque LSA 2. OSPF Router Information (RI) Opaque LSA
OSPF routers will optionally advertise their optional capabilities OSPF routers will optionally advertise their optional capabilities in
in an area-scoped, local scope, or AS-scoped Opaque-LSA [2]. an area-scoped, local scope, or AS-scoped Opaque-LSA [OPAQUE]. If a
If a router does not advertise this LSA, it does not imply that the router does not advertise this LSA, it does not imply that the router
router does not support one or more of the defined capabilities. does not support one or more of the defined capabilities. For
For existing OSPF capabilities, this advertisement will be used existing OSPF capabilities, this advertisement will be used primarily
primarily for informational purposes. For MPLS TE features, for informational purposes. For MPLS TE features, it is used for
it is used for advertisement and discovery. Future OSPF features advertisement and discovery. Future OSPF features could also use
could also use this mechanism for advertisement and discovery. this mechanism for advertisement and discovery. The RI opaque LSA
The RI opaque LSA will be originated when one of the advertised will be originated when one of the advertised capabilities is
capabilities is configured or changed. configured or changed.
The Router Information LSA will have an Opaque type of 4 and Opaque The Router Information LSA will have an Opaque type of 4 and Opaque
ID of 0. ID of 0.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LS age | Options | 9, 10 or 11 | | LS age | Options | 9, 10 or 11 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 4 | 0 | | 4 | 0 |
skipping to change at page 3, line 38 skipping to change at page 4, line 38
| Advertising Router | | Advertising Router |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LS sequence number | | LS sequence number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LS checksum | length | | LS checksum | length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
+- TLV's -+ +- TLV's -+
| ... | | ... |
Figure 2. OSPF Router Information LSA
The format of the TLV's within the body of a router information LSA The format of the TLV's within the body of a router information LSA
is the same as the format used by the Traffic Engineering is the same as the format used by the Traffic Engineering Extensions
Extensions to OSPF [4]. The LSA payload consists of one or to OSPF [TE]. The LSA payload consists of one or more nested Type/
more nested Type/Length/Value (TLV) triplets. The format of Length/Value (TLV) triplets. The format of each TLV is:
each TLV is:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Value... | | Value... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3. TLV Format
The Length field defines the length of the value portion in octets The Length field defines the length of the value portion in octets
(thus a TLV with no value portion would have a length of zero). The (thus a TLV with no value portion would have a length of zero). The
TLV is padded to four-octet alignment; padding is not included in TLV is padded to four-octet alignment; padding is not included in
the length field (so a three octet value would have a length of the length field (so a three octet value would have a length of
three, but the total size of the TLV would be eight octets). Nested three, but the total size of the TLV would be eight octets). Nested
TLV's are also 32-bit aligned. For example, a one byte value TLV's are also 32-bit aligned. For example, a one byte value would
would have the length field set to 1, and three bytes of padding have the length field set to 1, and three bytes of padding would be
would be added to the end of the value portion of the TLV. added to the end of the value portion of the TLV. Unrecognized types
Unrecognized types are ignored. are ignored.
2.1 OSPF Router Capabilities TLV 2.1 OSPF Router Capabilities TLV
The first defined TLV in the body of an RI opaque LSA is The first defined TLV in the body of an RI opaque LSA is the Router
the Router Capabilities TLV. A router advertising an RI opaque LSA Capabilities TLV. A router advertising an RI opaque LSA SHOULD
SHOULD include the Router Capabilities TLV and SHOULD correctly include the Router Capabilities TLV and SHOULD correctly identify the
identify the status of the capabilities defined in section 2.2. status of the capabilities defined in section 2.2.
The format of the Router Capabilities TLV is as follows: The format of the Router Capabilities TLV is as follows:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Capabilities | | Capabilities |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4. OSPF Router Capabilities TLV
Type A 16 bit field set to 1. Type A 16 bit field set to 1.
Length A 16 bit field that indicates the length of the value Length A 16 bit field that indicates the length of the value
portion in bytes. Its set to N x 4 octets. N starts portion in bytes. Its set to N x 4 octets. N starts
from 1 and can be increased when there is a need. Each 4 from 1 and can be increased when there is a need. Each 4
octets are referred to as a capability flag. octets are referred to as a capability flag.
Value This comprises one or more capability flags. For each 4 Value This comprises one or more capability flags. For each 4
octets, the bits are indexed from the most significant octets, the bits are indexed from the most significant
to the least significant, where each bit represents one to the least significant, where each bit represents one
router capability. When the first 32 capabilities are router capability. When the first 32 capabilities are
defined, a new capability flag will be used to defined, a new capability flag will be used to
accommodate the next capability. accommodate the next capability.
The Router Capabilities TLV MAY be followed by optional TLV's that The Router Capabilities TLV MAY be followed by optional TLV's that
further specify a capability. further specify a capability.
2.2 Reserved OSPF Router Capability Bits 2.2 Reserved OSPF Router Capability Bits
The following bits in the first capability flag have been The following bits in the first capability flag have been assigned:
assigned:
Bit Capabilities Bit Capabilities
0-3 Reserved 0-3 Reserved
4 OSPF graceful restart capable [5] 4 OSPF graceful restart capable [GRACE]
5 OSPF graceful restart helper [5] 5 OSPF graceful restart helper [GRACE]
6 Stub Router support [6] 6 OSPF Stub Router support [STUB]
7 Traffic Engineering support [4] 7 OSPF Traffic Engineering support [TE]
8 OSPF point-to-point over LAN [9] 8 OSPF point-to-point over LAN [P2PLAN]
9 OSPF Path Computation Server discovery [7, 8] 9 OSPF Path Computation Server discovery [TECAP]
10-31 Future assignments 10 OSPF Experimental TE [EXPTE]
11-31 Future assignments
2.3 Flooding Scope of the Router Information LSA 2.3 Flooding Scope of the Router Information LSA
The flooding scope for a Router Information opaque LSA is determined The flooding scope for a Router Information opaque LSA is determined
by the LSA type. A type 9 (link-scope), type 10 (area-scoped), or a by the LSA type. A type 9 (link-scope), type 10 (area-scoped), or a
type 11 (AS-scoped) opaque LSA may be flooded. If a type 11 opaque type 11 (AS-scoped) opaque LSA may be flooded. If a type 11 opaque
LSA is chosen, the originating router should also advertise type 10 LSA is chosen, the originating router should also advertise type 10
LSA(s) into any attached NSSA/stub area(s). An OSPF router MAY LSA(s) into any attached NSSA/stub area(s). An OSPF router MAY
advertise different capabilities when both NSSA/stub area type 10 advertise different capabilities when both NSSA/stub area type 10
LSA(s) and an AS scoped type 11 opaque LSA is advertised. The choice LSA(s) and an AS scoped type 11 opaque LSA is advertised. The choice
of flooding scope is made by the advertising router and is a matter of flooding scope is made by the advertising router and is a matter
of local policy. The originating router MAY advertise multiple RI of local policy. The originating router MAY advertise multiple RI
opaque LSAs as long as the flooding scopes differ. TLV flooding opaque LSAs as long as the flooding scopes differ. TLV flooding
scope rules will be specified on a per-TLV basis. scope rules will be specified on a per-TLV basis.
3. Security Consideration 3. Security Considerations
This memo does not create any new security issues for the OSPF This memo does not create any new security issues for the OSPF
protocol. Security considerations for the base OSPF protocol are protocol. Security considerations for the base OSPF protocol are
covered in [1]. covered in [OSPF].
4. Acknowledgments
The idea for this work grew out of a conversation with Andrew Partan
and we would like to thank him for his contribution. The authors
would like to thanks Peter Psenak for his review and helpful
comments early versions of the draft.
5. IANA Considerations 4. IANA Considerations
A new opaque LSA type will need to be assigned by IANA. A new opaque LSA type will need to be assigned by IANA.
Additionally, IANA will need to have registries for the Router Additionally, IANA will need to have registries for the Router
Information opaque LSA TLV's. The TLV assignee will be responsible Information opaque LSA TLV's. The TLV assignee will be responsible
for allocation of any sub-TLV's for the IANA assigned TLV. All for allocation of any sub-TLV's for the IANA assigned TLV. All TLV's
TLV's and sub-TLV's will be subject to OSPF WG review. and sub-TLV's will be subject to OSPF WG review.
6. References 5. References
Normative References 5.1 Normative References
[1] Coltun, R., "The OSPF Opaque LSA Option", RFC 2370, July [OSPF] Moy, J., "OSPF Version 2", RFC 2328, April 1998.
1998.
[2] Moy, J., "OSPF Version 2", RFC 2328, April 1998. [RFC2119] Bradner, S., "Key words for use in RFC's to Indicate
Requirement Levels", RFC 2328, March 1977.
[3] Bradner, S., "Key words for use in RFCs to Indicate Requirement [TE] Katz, D., Yeung, D. and K. Kompella, "Traffic Engineering
Level", BCP 14, RFC 2119, March 1997. Extensions to OSPF", RFC 3630, September 2003.
Informative References 5.2 Informative References
[4] Katz, D., D. Yeung and K. Kompella, "Traffic Engineering [EXPTE] Srisuresh, P. and P. Joseph, "OSPF OSPF-TE: An
Extensions to OSPF", RFC 3630, September 2003. experimental extension to OSPF for Traffic Engineering",
draft-srisuresh-ospf-te-07.txt (work in progress).
[5] Moy, J., P. Pillay-Esnault and A. Lindem, "OSPF Graceful [GRACE] Moy, J., Pillay-Esnault, P. and A. Lindem, "Graceful OSPF
OSPF Restart", RFC 3623, November 2003. Restart", RFC 3623, November 2003.
[6] Retana, A., et al, "OSPF Stub Router Advertisement", [OPAQUE] Coltun, R., "The OSPF Opaque LSA Option", RFC 2370, July
RFC 3137, June 2001. 1998.
[7] Vasseur, J., P. Psenak, "Traffic Engineering Capability TLV [P2PLAN] Shen, N. and A. Zinin, "Point-to-point operation over LAN
for OSPF", Internet Draft, work in progress. in link-state routing protocols",
draft-ietf-isis-igp-p2p-over-lan-05.txt (work in progress).
[8] Vasseur, J., et al, "RSVP Path computation request and reply [STUB] Retana, A., Nguyen, L., White, R., Zinin, A. and D.
messages", draft-vasseur-mpls-computation-rsvp-te-03.txt, McPherson, "OSPF Stub Router Advertisement", RFC 3137, June
work in progress 2001.
[9] N. Shen, et al, "Point-to-point operation over LAN in [T3CAP] Vasseur, JP., Psenak, P., Yasukawa, S. and JL. Le Roux,
link-state-routing protocols", Internet Draft, work in "OSPF MPLS Traffic Engineering Capabilities",
progress. draft-vasseur-ospf-te-caps-00.txt (work in progress).
7. Author Information Authors' Addresses
Acee Lindem Acee Lindem
Redback Networks Cisco Systems, Inc
350 Holger Way 7025 Kit Creek Road
San Jose, CA 95134 Research Triangle Park, NC 27709
e-mail: acee@redback.com USA
EMail: acee@cisco.com
Naiming Shen Naiming Shen
Redback Networks BCN Networks, Inc
350 Holger Way 2975 San Ysidro Way
San Jose, CA 95134 Santa Clara, CA 95051
e-mail: naiming@redback.com USA
EMail: naiming@bcn-inc.net
Rahul Aggarwal Rahul Aggarwal
Juniper Networks Juniper Networks
1194 N. Mathilda Ave. 1194 N. Mathilda Ave.
Sunnyvale, CA 94089 USA Sunnyvale, CA 94089
e-mail: rahul@juniper.net USA
Scott Shaffer EMail: rahul@juniper.net
Level 3 Communications
e-mail: scott.shaffer@level3.com
JP Vasseur Scott Schaffer
Cisco Systems, Inc. BridgePort Networks
300 Apollo Drive One Main Street, 7th Floor
Chelmsford, MA 01824 Cambridge, MA 02142
e-mail: jpv@cisco.com USA
8. Full Copyright Statement EMail: sschafferl@bridgeport-networks.com
Copyright (C) The Internet Society (2004). This document is subject Jean-Philippe Vasseur
to the rights, licenses and restrictions contained in BCP 78 and Cisco Systems, Inc
except as set forth therein, the authors retain all their rights. 300 Beaver Brook Road
Boxborough, MA 01719
USA
This document and translations of it may be copied and furnished to EMail: jpv@cisco.com
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
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included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
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followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be Appendix A. Acknowledgments
revoked by the Internet Society or its successors or assignees.
This document and the information contained herein is provided on an The idea for this work grew out of a conversation with Andrew Partan
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING and we would like to thank him for his contribution. The authors
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING would like to thanks Peter Psenak for his review and helpful comments
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION early versions of the draft.
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
9. Intellectual Property The RFC text was produced using Marshall Rose's xml2rfc tool.
Intellectual Property Statement
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Acknowledgment
Funding for the RFC Editor function is currently provided by the Funding for the RFC Editor function is currently provided by the
Internet Society. Internet Society.
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