Specifications

Configuring Routing Between VLANs
How to Configure Routing Between VLANS
30
DETAILED STEPS
Configuring IS-IS Routing over ISL
IS-IS routing can be enabled over VLAN subinterfaces using the ISL VLAN encapsulation protocol. The
IS-IS Routing over ISL Virtual LANs feature provides full-feature Cisco IOS software IS-IS support on
a per-VLAN basis, allowing standard IS-IS capabilities to be configured on VLANs.
To enable IS-IS over ISL VLANs, you need to configure ISL encapsulation on the subinterface. Perform
the steps described in the following task in the order in which they appear.
SUMMARY STEPS
1. enable
2. configure terminal
3. router isis [tag]
4. net network-entity-title
5. interface type slot/port.subinterface-number
6. encapsulation isl vlan-identifier
7. clns router isis network [tag]
Command or Action Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2
configure terminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
clns routing
Example:
Router(config)# clns routing
Enables CLNS routing globally.
Step 4
interface type slot/port.subinterface-number
Example:
Router(config-if)# interface fastethernet 1/0.1
Specifies the subinterface on which ISL will be used.
Step 5
encapsulation isl vlan-identifier
Example:
Router(config-if)# encapsulation isl 100
Defines the encapsulation format as ISL (isl), and specifies
the VLAN identifier.
Step 6
clns enable
Example:
Router(config-if)# clns enable
Enables CLNS routing on the subinterface.