Configuring IS-IS Priority

The priority is used to determine the designated router. The intermediate system with the highest priority becomes the designated router. IS-IS does not support the concept of a backup designated router. Setting the priority to 0 does not prevent this system from becoming the designated router. If priorities are equal, the interface with the highest MAC address breaks the tie. Priority defaults to 64.

The following example shows how to configure VLAN 100 for a priority of 80:

System(rw)->configure
System(rw-config)->interface vlan 100
System(rw-config-intf-vlan.0.100)->isis priority 80
System(rw-config-intf-vlan.0.100)->