Extensions For Traffic Engineering; Integrated Is-Is - Juniper JUNOSE SOFTWARE FOR E SERIES 11.3.X - IP-IPV6-IGP CONFIGURATION GUIDE 2010-10-31 Configuration Manual

Extensions for Traffic Engineering

Integrated IS-IS

Copyright © 2010, Juniper Networks, Inc.
When you suppress authentication of CSNPs, the router does not authenticate CSNP
packets that it receives from neighboring routers, nor does it include authentication
information in CSNP packets that it sends to other routers. Similarly, when you suppress
authentication of PSNPs, the router neither authenticates PSNP packets that it receives
nor sends authentication information in PSNP packets that it transmits.
The router supports new-style TLV tuples described in the Internet draft, IS-IS Extensions
for Traffic Engineering. The router ID TLV (TLV type 134) contains the ID of the router that
originates the LSP, providing a stable address that can always be referenced regardless
of the state of node interfaces.
The extended IP reachability TLV (type 135) carries IP prefixes and is similar to the IP
reachability TLVs (types 128 and 130). The extended IS reachability TLV (type 22) contains
information about a series of IS neighbors and is similar to the IS neighbor TLV (type 2).
The older TLVs—2, 128, 130—each have a narrow metric field, providing for metric values
ranging only from 0–63. The new TLVs—22 and 135—have a new data structure that
includes a wide metric field of 3 bytes (extended IS reachability; configurable) or four
bytes (extended IP reachability; calculated). Both new TLVs provide for the use of
sub-TLVs to carry more information about IS neighbors; however, only the extended IS
reachability TLV currently has defined sub-TLVs, such as IPv4 interface and neighbor
addresses.
Use the metric-style commands to configure what style the router generates and accepts.
The following behaviors are supported:
Generates and accepts only old-style metrics
Generates only old-style metrics, but accepts old style and new style
Generates and accepts both old-style and new-style metrics (this option consumes
the most system resources)
Generates only new-style metrics, but accepts old style and new style
Generates and accepts only new-style metrics
Refer to the Internet draft, IS-IS Extensions for Traffic Engineering, for more information
about these extensions.
The E Series router supports the Integrated IS-IS version of IS-IS. Integrated IS-IS provides
a single routing algorithm to route both TCP/IP and OSI Connectionless Network Protocol
(CLNP) packets. This design adds IP-specific information to the OSI IS-IS routing protocol.
It supports IP subnetting, variable subnet masks, type of service (ToS), and external
routing.
Integrated IS-IS allows for the mixing of routing domains; that is, IP-only routers, OSI-only
routers, and dual (IP and OSI) routers. OSI and IP packets are forwarded directly over
the link-layer services without needing mutual encapsulation. The E Series router supports
Chapter 6: Configuring IS-IS
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