Chapter 16: Dynamic Routing Protocols
STANDARD Revision 1.0
C4® CMTS Release 8.3 User Guide
© 2016 ARRIS Enterprises LLC. All Rights Reserved.
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Circuit Admin State: enabled, Oper State: Up
Level-1
Metric: 10, Wide-metric: 10, Priority: 64, Circuit Id: E6-22.00
Hello Timer: 3000msec, Hello Multiplier: 10, DRHello Timer:
1000msec
LSP Throttle: 30msec, LSP Retransmit Interval: 5sec
Number of active level-1 adjacencies: 1
Multiple Topology IS-IS
Multiple Topology IS-IS Overview
The C4/c CMTS software supports two topologies for IS-IS:
IPv4
IPv6
IS-IS could be configured as IPv4 only, IPv6 only, or IPv4-IPv6 only, but only a single Shortest Path First (SPF) would run per
level for IPv4 or IPv6.
Overcoming Single SPF Limitation
To overcome the single SPF limitation, Multiple Topology IS-IS (MT IS-IS) is implemented in the C4/c CMTS.
When MT IS-IS is enabled, the C4/c CMTS will maintain multiple instances of the IS-IS routing tree and will run two
separate SPFs:
One for standard topology IPv4
The other for IPv6 topology
In the example of the figure below, Router B in Area 1 is IPv4 only, and all other routers are IPv4-IPv6.