Reference Guide

Intermediate System to Intermediate System (IS-IS) | 927
Parameters
Defaults
value = 64; level-1 (if not otherwise specified)
Command Modes
INTERFACE
Command
History
Usage
Information
You can configure priorities independently for Level 1 and Level 2. Priorities determine which router
on a LAN will be the designated router. Priorities are advertised within hellos. The router with the
highest priority will become the designated intermediate system (DIS).
Routers with a priority of 0 cannot be a designated router. Setting the priority to 0 lowers the chance of
this system becoming the DIS, but does not prevent it. If all the routers have priority 0, one with
highest MAC address will become DIS even though its priority is 0.
is-type
e
Configure IS-IS operating level for a router.
Syntax
is-type {level-1 | level-1-2 | level-2-only}
To return to the default values, enter no is-type.
Parameters
Defaults
level-1-2
Command Modes
ROUTER ISIS
Command
History
Usage
Information
The IS-IS protocol automatically determines area boundaries and are able to keep Level 1 and Level 2
routing separate. Poorly planned use of this feature may cause configuration errors, such as accidental
area partitioning.
value
This value sets the router priority. The higher the value, the higher the priority.
Range: 0 to 127
Default: 64
level-1
(OPTIONAL) Specify the priority for Level 1.
This is the default.
level-2
(OPTIONAL) Specify the priority for Level 2.
Version 8.3.19.0 Introduced on S4820T
Version 8.3.12.0 Introduced on S4810
level-1
Allows a router to act as a Level 1 router.
level-1-2
Allows a router to act as both a Level 1 and Level 2 router.
This is the default.
level-2-only
Allows a router to act as a Level 2 router.
Version 8.3.19.0 Introduced on S4820T
Version 8.3.12.0 Introduced on S4810