Internet N. Shen Internet-Draft E. Chen Expires: May 2007 Cisco Systems November 2006 ICMP Extensions for Routing Instances draft-shen-icmp-routing-inst-00.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on March, 2007. Copyright Notice Copyright (C) The Internet Society (2006). Abstract This document specifies the extensions to ICMP that allows routing instance information to be included inside the ICMP packet. These extensions can be used to facilitate the troubleshooting network problems within a routing domain or across multiple routing domains. 1. Conventions Used In This Document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC2119 [10]. Shen, Chen Expires May 2007 [Page 1] Internet-Draft ICMP Routing Instance November 2006 2. Introduction Internet Control Message Protocol (ICMP) [1] has been widely used for troubleshooting purposes. This document utilizes the ICMP multi-part message extension [2] to define a number of important routing instance objects in ICMP messages. When using traceroute diagnostic tool through multiple routing domains, it is useful to have ICMP Time exceeded messages to include the AS number [3] the router or virtual router belongs to. Within the same routing domain, if a network operates with multiple topologies for IGP [4, 5], it is crucial in network troubleshooting to know the multi-topology identifier the traceroute packet of inbound interface is associated with. This information can be included in the ICMP messages. With the traditional Interior Gateway Protocol (IGP) diagnostics, it is useful for the ICMP Time exceeded messages to report OSPF area [6] the router belongs to or to report the IS-IS [7] level the router or link belong to when the IGP being IS-IS. The OSPF area and IS-IS level can also belong to a specific routing instance the inbound interface is associated with for the traceroute packets. A router may support VRRP [9] over a LAN interface and it is informative to know if the interface has redundancy protection and it's configured virtual router identifier (VRID). 3. ICMP Multiple-part Message Extension This document uses the ICMP extension [2]. The ICMP message MUST include the IP header and leading payload octets of the original datagram. An ICMP Extension Structure Header MUST follow the octets from the original datagram and come before any ICMP Extension Objects. 4. Routing Objects for ICMP This section defines a number of ICMP routing instance objects that can be optionally appended to the ICMP Time Exceeded and Destination Unreachable messages. 4.1 Autonomous System Number Object The router MAY include the AS number [3] when sending out the ICMP messages. Shen, Chen Expires May 2007 [Page 2] Internet-Draft ICMP Routing Instance November 2006 Class-Num = 5 C-type = 1 Length = 8 Object payload: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | AS Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: AS Number Object 4.2 Multi-Topology ID Object The router MAY include the MT ID [4, 5] when sending out the ICMP messages. Class-Num = 5 C-type = 2 Length = 8 Object payload: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved | MT ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: MT ID Object The MT ID is a 12 bit number for IS-IS MT, and it is a 7 bit number for OSPF. 4.3 OSPF Area ID Object The router MAY include the Area ID for OSPF [6] when sending out the ICMP messages. Class-Num = 5 C-type = 3 Length = 8 Object payload: Shen, Chen Expires May 2007 [Page 3] Internet-Draft ICMP Routing Instance November 2006 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Area ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: OSPF Area ID Object 4.4. IS-IS Level Object The router MAY include the IS-IS level [7] when sending out the ICMP messages. Class-Num = 5 C-type = 4 Length = 8 Object payload: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Instance ID | Reserved | Level | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 4: IS-IS Level Object The Instance ID is a 16 bit number [11], default value is zero. The Level is a 8 bit number, currently defined as following: 1 - IS-IS level-1 2 - IS-IS level-2 3 - IS-IS level-1-2 4.5 IGRP and EIGRP AS ID Object The router MAY include the IGRP AS ID or EIGRP AS Number when sending out the ICMP messages. Class-Num = 5 C-type = 5 Length = 8 Object payload: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IGRP or EIGRP AS ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 5: IGRP or EIGRP AS ID Object Shen, Chen Expires May 2007 [Page 4] Internet-Draft ICMP Routing Instance November 2006 The IGRP/EIGRP AS ID is a 32 bit number. 4.6 Virtual Router Identifier Object The router MAY include the virtual router identifier of VRRP [9] when sending out the ICMP messages. Class-Num = 5 C-type = 6 Length = 8 Object payload: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved | VR ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 6: VRID Object Virtual Router ID is an 8 bit number. 5. Security Considerations These ICMP extensions can provide operators with additional routing information during network troubleshooting. It may be desirable to provide this information only to network operators. This may be desirable in particular for the IGP routing related objects. The implementation should allow the configuration of the policy control over the operation of these objects. For example, an access list can be attached to check the IP destination of the ICMP packets with this extension belong to internal network management subnet. 6. IANA Considerations IANA should should reserve from the ICMP Extension Object registry: 5 for the routing instance objects. IANA should also reserve from the objects c-types as described in section 4 of this document. 7. Acknowledgement TBA. 8. References 8.1. Normative References Shen, Chen Expires May 2007 [Page 5] Internet-Draft ICMP Routing Instance November 2006 [1] Postel, J., "Internet Control Message Protocol", STD 5, RFC 792, September 1981. [2] Bonica, R., "Modifying ICMP to Support Multi-part Messages", draft-bonica-internet-icmp-12 (work in progress), October 2006. [3] Y. Rekhter., "A Border Gateway Protocol 4 (BGP-4)", RFC 4271, January 2006. [4] Przygienda, T., "M-ISIS: Multi Topology (MT) Routing in IS-IS", draft-ietf-isis-wg-multi-topology-11 (work in progress), April 2006. [5] Psenak, P., "Multi-Topology (MT) Routing in OSPF", draft-ietf-ospf-mt-06 (work in progress), February 2006. [6] Moy, J., "OSPF Version 2", RFC 2328, April 1998. [7] ISO, "Intermediate system to Intermediate system routing information exchange protocol for use in conjunction with the Protocol for providing the Connectionless-mode Network Service (ISO 8473)," ISO/IEC 10589:1992. [8] Vohra, Q., "BGP Support for Four-octet AS Number Space", draft-ietf-idr-as4bytes-12 (work in progress), May 2006. [9] Hinden, R., "Virtual Router Redundancy Protocol (VRRP)" RFC 2338, April 2004. [10] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [11] Previdi, S., "IS-IS Multi-instance Multi-topology", draft-previdi-isis-mi-mt-01.txt (work in progress), June 2006. Author's Addresses Naiming Shen Cisco Systems 225 West Tasman Drive San Jose, CA 95134 USA Email: naiming@cisco.com Enke Chen Cisco Systems 170 West Tasman Drive San Jose, CA 95134 USA Email: enkechen@cisco.com Shen, Chen Expires May 2007 [Page 6] Internet-Draft ICMP Routing Instance November 2006 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. 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Disclaimer of Validity This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Copyright Statement Copyright (C) The Internet Society (2006). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Shen, Chen Expires May 2007 [Page 7]