Administrator Guide

isis circuit-type
Configure the adjacency type on interfaces.
Syntax
isis circuit-type {level-1 | level-1-2 | level-2-only}
To return to the default values, use the no isis circuit-type command.
Parameters
level-1 You can form a Level 1 adjacency if there is at least one
common area address between this system and neighbors.
You cannot form Level 2 adjacencies on this interface.
level-1-2 You can form a Level 1 and Level 2 adjacencies when the
neighbor is also configured as Level-1-2 and there is at least
one common area, if not, a Level 2 adjacency is established.
This setting is the default.
level-2-only You can form a Level 2 adjacencies when other Level 2 or
Level 1-2 routers and their interfaces are configured for Level
1-2 or Level 2. Level 1 adjacencies cannot be established on
this interface.
Defaults level-1-2
Command
Modes
INTERFACE
Command
History
This guide is platform-specific. For command information about other platforms,
refer to the relevant Dell Networking OS Command Line Reference Guide.
The following is a list of the Dell Networking OS version history for this command.
Version Description
9.7(0.0) Introduced on the S6000-ON.
9.0.2.0 Introduced on the S6000.
8.3.19.0 Introduced on the S4820T.
8.3.12.0 Introduced on the S4810.
8.3.11.1 Introduced on the Z9000.
Usage
Information
Because the default establishes Level 1 and Level 2 adjacencies, you do not need to
configure this command. Routers in an IS-IS system must be configured as a Level
1-only, Level 1-2, or Level 2-only system.
Only configure interfaces as Level 1 or Level 2 on routers that are between areas
(for example, a Level 1-2 router) to prevent the software from sending unused hello
packets and wasting bandwidth.
902
Intermediate System to Intermediate System (IS-IS)