Skip to main content

IS-IS Extended Hierarchy

Document Type Expired Internet-Draft (lsr WG)
Expired & archived
Authors Tony Li , Les Ginsberg , Paul Wells
Last updated 2022-12-30 (Latest revision 2022-06-28)
Replaces draft-li-lsr-isis-hierarchical-isis
RFC stream Internet Engineering Task Force (IETF)
Intended RFC status (None)
Additional resources Mailing list discussion
Stream WG state WG Document
Document shepherd Christian Hopps
IESG IESG state Expired
Consensus boilerplate Unknown
Telechat date (None)
Responsible AD (None)
Send notices to

This Internet-Draft is no longer active. A copy of the expired Internet-Draft is available in these formats:


The IS-IS routing protocol was originally defined with a two level hierarchical structure. This was adequate for the networks at the time. As we continue to expand the scale of our networks, it is apparent that additional hierarchy would be a welcome degree of flexibility in network design. This document defines IS-IS Levels 3 through 8.


Tony Li
Les Ginsberg
Paul Wells

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)