Dynamic Hostname Exchange Mechanism for IS-IS
The information below is for an old version of the document that is already published as an RFC.
This is an older version of an Internet-Draft that was ultimately published as RFC 5301.
|Authors||Naiming Shen , Danny R. McPherson|
|Last updated||2018-12-20 (Latest revision 2007-09-30)|
|RFC stream||Internet Engineering Task Force (IETF)|
|Additional resources||Mailing list discussion|
|IESG||IESG state||RFC 5301 (Proposed Standard)|
|Responsible AD||Ross Callon|
|Send notices to||(None)|
INTERNET-DRAFT Danny McPherson Arbor Networks Naiming Shen Cisco Systems Expires: March 2008 September 30, 2007 Intended Status: Proposed Standard Dynamic Hostname Exchange Mechanism for IS-IS <draft-ietf-isis-rfc2763bis-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/1id-abstracts.html The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html Copyright Notice Copyright (C) The IETF Trust (2007). McPherson, Shen [Page 1] INTERNET-DRAFT Expires: March 2008 September 2007 Abstract Currently, there does not exist a simple and dynamic mechanism for routers running IS-IS to learn about symbolic hostnames. This document defines a new TLV which allows the IS-IS routers to flood their name-to-systemID mapping information across the IS-IS network. The intention of this document is to provide an update to [RFC 2763]. McPherson, Shen [Page 2] INTERNET-DRAFT Expires: March 2008 September 2007 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1. Specification of Requirements . . . . . . . . . . . . . . . 4 2. Possible Solutions . . . . . . . . . . . . . . . . . . . . . . 4 3. Dynamic Hostname TLV . . . . . . . . . . . . . . . . . . . . . 5 4. Implementation . . . . . . . . . . . . . . . . . . . . . . . . 6 5. Security Considerations. . . . . . . . . . . . . . . . . . . . 6 6. Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . . 6 7. IANA Considerations. . . . . . . . . . . . . . . . . . . . . . 7 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 8 8.1. Normative References. . . . . . . . . . . . . . . . . . . . 8 8.2. Informative References. . . . . . . . . . . . . . . . . . . 8 9. Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 8 McPherson, Shen [Page 3] INTERNET-DRAFT Expires: March 2008 September 2007 1. Introduction IS-IS uses a variable 1-8 byte system ID (normally 6 bytes) to represent a node in the network. For management and operation reasons, network operators need to check the status of IS-IS adjacencies, entries in the routing table and the content of the IS- IS link state database. It is obvious that, when looking at diagnostics information, hexadecimal representations of systemIDs and LSP identifiers are less clear than symbolic names. One way to overcome this problem is to define a name-to-systemID mapping on a router. This mapping can be used bidirectionally. E.g., to find symbolic names for systemIDs, and to find systemIDs for symbolic names. One way to build this table of mappings is by static definitions. Among network administrators who use IS-IS as their IGP it is current practice to define such static mappings. Thus every router has to maintain a statically configured table with mappings between router names and systemIDs. These tables need to contain all names and systemIDs of all routers in the network, and must be modified each time an addition, deletion or change occurs.. There are several ways one could build such a table. One is via static configurations. Another scheme that could be implemented is via DNS lookups. In this document we propose a third solution. We hope the proposed solution is easier and more manageable than static mapping or DNS schemes, and wide-scale implementation and deployment of this capability has proved this to be the case. 1.1. Specification of Requirements The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC 2119]. 2. Possible Solutions The obvious drawback of static configuration of mappings is the issue of scalability and maintainability. The network operators have to maintain the name tables. They have to maintain an entry in the table for every router in the network, on every router in the network. The McPherson, Shen Section 2. [Page 4] INTERNET-DRAFT Expires: March 2008 September 2007 effort to create and maintain these static tables grows with the total number of routers on the network. Changing the name or systemID of one router, or adding one new router introduced will affect the configurations of all the other routers on the network. This will make it very likely that those static tables are outdated. Having one table that can be updated in a centralized place would be helpful. One could imagine using the DNS system for this. A drawback is that during the time of network problems, the response time of DNS services might not be satisfactory or the DNS services might not even be available. Another possible drawback might be the added complexity of DNS. Also, some DNS implementations might not support A and PTR records for CLNS NSAPs. A third way to build dynamic mappings would be to use the transport mechanism of the routing protocol itself to advertise symbolic names in IS-IS link-state PDUs. This document defines a new TLV which allows the IS-IS routers to include the name-to-systemID mapping data in their LSPs. This will allow simple and reliable transport of name mapping information across the IS-IS network. 3. Dynamic Hostname TLV The Dynamic hostname TLV is defined here as TLV type 137. LENGTH - total length of the value field. VALUE - a string of 1 to 255 bytes. The Dynamic hostname TLV is optional. This TLV may be present in any fragment of a non-pseudo node LSP. The value field identifies the symbolic name of the router originating the LSP. This symbolic name can be the FQDN for the router, it can be a subset of the FQDN or any string operators want to use for the router. The use of FQDN or a subset of it is strongly recommended. The content of this value is a domain name, see [RFC 2181]. The string is not null-terminated. The systemID of this router can be derived from the LSP identifier. If this TLV is present in a pseudo node LSP, then it SHOULD NOT be interpreted as the DNS hostname of the router. McPherson, Shen Section 3. [Page 5] INTERNET-DRAFT Expires: March 2008 September 2007 4. Implementation The Dynamic Hostname TLV is optional. When originating an LSP, a router may decide to include this TLV in its LSP. Upon receipt of an LSP with the dynamic hostname TLV, a router may decide to ignore this TLV, or to install the symbolic name and systemID in its hostname mapping table for the IS-IS network. A router may also optionally insert this TLV in it's pseudo node LSP for the association of a symbolic name to a local LAN. 5. Security Considerations This document raises no new security issues for IS-IS. 6. Acknowledgments The original efforts and corresponding acknowledgements provided in [RFC 2763] have enabled this work. In particular, we'd like to acknowledge Henk Smit as an author of that document. Others to be provided.... McPherson, Shen Section 6. [Page 6] INTERNET-DRAFT Expires: March 2008 September 2007 7. IANA Considerations This document specificies TLV 137, "Dynamic Name". This TLV has already been allocated and reserved [RFC 2763]. As such, no new actions are required on the part of IANA. McPherson, Shen Section 7. [Page 7] INTERNET-DRAFT Expires: March 2008 September 2007 8. References 8.1. Normative References [ISO 8473] ISO, "Intermediate system to Intermediate system routeing information exchange protocol for use in conjunction with the Protocol for providing the Connectionless-mode Network Service (ISO 8473)," ISO/IEC 10589:1992. 8.2. Informative References [RFC 2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, March 1997. [RFC 2181] Elz, R., Bush, R., "Clarifications to the DNS Specification", RFC 2181, July 1997. [RFC 2763] Smit, H., Shen, N., "Dynamic Hostname Exchange Mechanism for IS-IS, RFC 2763, February 2000. 9. Authors' Addresses Danny McPherson Arbor Networks, Inc. EMail: firstname.lastname@example.org Naiming Shen Cisco Systems, Inc. EMail: email@example.com 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 McPherson, Shen Section 9. [Page 8] INTERNET-DRAFT Expires: March 2008 September 2007 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. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at firstname.lastname@example.org. Copyright Statement Copyright (C) The IETF Trust (2007). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Acknowledgment Funding for the RFC Editor function is provided by the IETF Administrative Support Activity (IASA). McPherson, Shen Section 9. [Page 9]