TRILL Working Group Radia Perlman
INTERNET-DRAFT Intel Labs
Intended status: Informational Donald Eastlake
Huawei
Anoop Ghanwani
Dell
Hongjun Zhai
ZTE
Expires: June 4, 2012 December 5, 2012
Alternatives for Multilevel TRILL
(Transparent Interconnection of Lots of Links)
<draft-perlman-trill-rbridge-multilevel-05.txt>
Abstract
This is an informational document describing issues and comparing
general advantages and disadvantages of various approaches to
extending TRILL (Transparent Interconnection of Lot of Links) to use
multilevel IS-IS (Intermediate System to Intermediate System) routing
to improve TRILL's scalability.
Status of This Memo
This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79. Distribution of this document is
unlimited. Comments should be sent to the TRILL working group
mailing list <rbridge@postel.org>.
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.
Acknowledgements
The helpful comments of the following are hereby acknowledged: David
Michael Bond and Dino Farinacci.
R. Perlman, et al [Page 1]
INTERNET-DRAFT Multilevel TRILL
Table of Contents
1. Introduction............................................3
1.1 TRILL Scalability Issues...............................3
1.2 Improvements Due to Multilevel.........................4
1.3 More on Areas..........................................5
1.4 Terminology and Acronyms...............................5
2. Multilevel TRILL Issues.................................6
2.1 Non-zero Area Addresses................................7
2.2 Aggregated versus Unique Nicknames.....................7
2.2.1 More Details on Unique Nicknames.....................8
2.2.2 More Details on Aggregated Nicknames.................9
2.2.2.1 Border Learning Aggregated Nicknames...............9
2.2.2.2 Swap Nickname Field Aggregated Nicknames..........11
2.2.2.3 Comparison........................................12
2.3 Building Multi-Area Trees.............................12
2.4 The RPF Check for Trees...............................13
2.5 Area Nickname Acquisition.............................13
2.6 Link State Representation of Areas....................14
3. Area Partition.........................................15
4. Multi-Destination Scope................................16
4.1 Unicast to Multi-destination Conversions..............16
4.1.1 New Tree Encoding...................................17
4.2 Selective Broadcast Domain Reduction..................17
5. Co-Existence with Old RBridges.........................19
6. Multi-Access Links with End Stations...................20
7. Summary................................................21
8. Security Considerations................................21
9. IANA Considerations....................................21
10. Normative References..................................22
11. Informative References................................22
R. Perlman, et al [Page 2]
INTERNET-DRAFT Multilevel TRILL
1. Introduction
The IETF TRILL (Transparent Interconnection of Lot of Links) protocol
[RFC6325] provides optimal pair-wise data frame forwarding without
configuration, safe forwarding even during periods of temporary
loops, and support for multipathing of both unicast and multicast
datatracker.ietf.org