OSPF Working Group Venkata Naidu Internet Draft Sanjay Harwani Expiration Date: Marconi Communications File name: draft-venkata-ospf-dynamic-hostname-00.txt June 2002 Dynamic Hostname Exchange Mechanism for OSPF Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. 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. Abstract Currently, there does not exist a simple and dynamic mechanism for routers running OSPF to learn about symbolic hostnames just like ISIS. This document defines a new Area Scope and AS Scope Opaque LSAs which allows the OSPF routers to flood their name to Router ID mapping information across the OSPF network. Naidu & Harwani Informational [Page 1]
Internet Draft Dynamic Hostname June 2002 1. Introduction OSPF uses a 4 byte Router ID to represent a node in the network. For management and operation reasons, network operators need to check the status of OSPF adjacencies, entries in the routing table and the content of the OSPF link state database. It is obvious that, when looking at diagnostics information, (dotted)decimal representations of Router IDs are less clear than symbolic names. One way to overcome this problem is to define a name-to-Router ID mapping on a router. This mapping can be used bidirectionally. E.g., to find symbolic names for Router IDs, and to find Router IDs for symbolic names. One way to build this table of mappings is by static definitions. Thus every router has to maintain a table with mappings between router names and Router IDs. These tables need to contain all names and Router IDs of all routers in the network. 2. Possible solutions All possible solutions are described in [RFC2763]. 3. Implementation This extension makes use of the Opaque LSA [RFC2370]. Three types of Opaque LSAs exist, each of which has different flooding scope. This proposal uses only Type 10 and Type 11 LSAs, which have area And AS flooding scope respectively. The Dynamic Hostname LSAs are optional. Upon receipt of an LSA with the dynamic hostname TLV, a router may decide to ignore this TLV, or to install the symbolic name and Router ID in its hostname mapping table. Naidu & Harwani Informational [Page 2]
Internet Draft Dynamic Hostname June 2002 3.1 The Area Scope Dynamic Hostname LSA Format Area Scope Opaque LSA is extended to flood the new Dynamic hostname LSA defined here as LSA ID TBD. The Dynamic Hostname LSA starts with the standard LSA header: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | LS age | Options | 10 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TBD | Reserved | Instance | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Advertising Router | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | LS sequence number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | LS checksum | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Length - total length of Dynamic Hostname LSA. 3.1.1. TLV Header The LSA payload consists of one or more nested Type/Length/Value (TLV) triplets for extensibility. The format of each TLV is: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Value... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type - Dynamic Host Name TLV Type (TBD) Length - total length of the value field. Value - a string of 1 to 255 bytes. The value field identifies the symbolic name of the router originating the LSA. The string is not null-terminated. The Router ID of this router can be derived from the LSA header. Naidu & Harwani Informational [Page 3]
Internet Draft Dynamic Hostname June 2002 3.2 The AS Scope Dynamic Hostname LSA Format AS Scope Opaque LSA is extended to flood the new Dynamic hostname LSA defined here as LSA ID TBD. A Router originating AS scope Dynamic Hostname LSA MAY ignore sending an Area scope Dynamic Hostname LSA, because AS scope LSAs are flooded through out OSPF domain transparently (except stub and NSSA areas). The Dynamic Hostname LSA starts with the standard LSA header: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | LS age | Options | 10 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TBD | Reserved | Instance | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Advertising Router | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | LS sequence number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | LS checksum | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Length - total length of Dynamic Hostname LSA. 3.2.1. TLV Header The LSA payload consists of one or more nested Type/Length/Value (TLV) triplets for extensibility. The format of each TLV is: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Value... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type - Dynamic Host Name TLV Type (TBD) Length - total length of the value field. Value - a string of 1 to 255 bytes. The value field identifies the symbolic name of the router originating the LSA. The string is not null-terminated. The Router ID of this router can be derived from the LSA header. Naidu & Harwani Informational [Page 4]
Internet Draft Dynamic Hostname June 2002 4. Security Considerations This document raises no new security issues for OSPF. However, it is encouraged to use authentications for OSPF routing protocol. The authentication mechanism for OSPF protocol is specified in [RFC2328]. 5. Acknowledgments The authors of this document do not make any claims on the originality of the ideas described. The authors would like to thank authors of similar work done in ISIS RFC 2763. 6. References [RFC2328] Moy, J., "OSPF Version 2," RFC 2328, Ascend Communications Corp., April 1998. [RFC2370] Coltun, Rob, "The OSPF Opaque LSA Option," RFC 2370, FORE Systems, July 1998. [RFC2763] Shen, Naiming and Smit, Henk, "Dynamic Hostname Exchange Mechanism for ISIS," RFC 2763, February 2000. 7. Authors' Addresses Venkata Naidu Phone: (703) 245-4562 EMail: Venkata.Naidu@Marconi.com Sanjay Harwani Phone: (703) 245-4587 EMail: Sanjay.Harwani@Marconi.com Marconi Communications 1595 Spring Hill Rd, 5th Floor Vienna VA 22031 Naidu & Harwani Informational [Page 5]