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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Adjacencies
Adjacencies formed are based on interface circuit-type (either Level 1, Level 2, or both) and the provisioned area ID in the
NSAP address.
Note: The circuit-type is encoded in the Intermediate System to Intermediate System Hello (IIH) packet.
The figure above defines the following adjacencies:
Router R1: Circuits are Level 2 only since the router resides completely in a Level 2 area. R1 will form Level 2
adjacencies with R2 and R3.
Routers R2 and R3: These routers are considered Border routers since north-bound circuits are defined as Level 2, and
south-bound circuits are defined as Level 1. R2 defines adjacencies with R1 and R5 while R3 defines adjacencies with
R1 and R4.
Routers R4 and R5: Circuits may be defined as Level 1 only since these are edge routers connected to the IS-IS
backbone.
Dynamic Hostname Support
The C4/c CMTS will support use of the dynamic hostname in IS-IS link state packets (LSPs). The C4/c CMTS will support the
use of TLV 137 to communicate its hostname and receive hostname updates from peer routers.
In the IS-IS routing domain, a system ID is used to represent each router. The system ID is part of the network entity title
that is configured for each IS-IS router.
The dynamic hostname mechanism uses link-state protocol (LSP) flooding to distribute the router-name-to-system-ID
mapping information across the entire network. Every router on the network will try to install the system ID-to-router
name mapping information in its routing table.
To enable the C4/c CMTS to send dynamic hostname Type-Length-Value (TLV) for IS-IS routes, use the following command:
configure router isis hostname dynamic
The default value is enabled and will persist across a system reboot. To turn off dynamic hostname TLV sending, use the
following command:
configure router isis hostname dynamic no
Note: Receiving, decoding, and processing Dynamic Hostname TLVs from peer routers is always on.