•Configuring the IS-IS Metric Style
•Configuring the IS-IS Cost
•Changing the IS-Type
•Controlling Routing Updates
•Configuring Authentication Passwords
•Setting the Overload Bit
•Debugging IS-IS
Enabling IS-IS
By default, IS-IS is not enabled.
The system supports one instance of IS-IS. To enable IS-IS globally, create an IS-IS routing process and
assign a NET address. To exchange protocol information with neighbors, enable IS-IS on an interface,
instead of on a network as with other routing protocols.
In IS-IS, neighbors form adjacencies only when they are same IS type. For example, a Level 1 router never
forms an adjacency with a Level 2 router. A Level 1-2 router forms Level 1 adjacencies with a neighboring
Level 1 router and forms Level 2 adjacencies with a neighboring Level 2 router.
NOTE: Even though you enable IS-IS globally, enable the IS-IS process on an interface for the IS-IS
process to exchange protocol information and form adjacencies.
To configure IS-IS globally, use the following commands.
1. Create an IS-IS routing process.
CONFIGURATION mode
router isis [tag]
tag: (optional) identifies the name of the IS-IS process.
2. Configure an IS-IS network entity title (NET) for a routing process.
ROUTER ISIS mode
net network-entity-title
Specify the area address and system ID for an IS-IS routing process. The last byte must be 00.
For more information about configuring a NET, refer to IS-IS Addressing.
3. Enter the interface configuration mode.
CONFIGURATION mode
interface interface
Enter the keyword interface then the type of interface and slot/port information:
• For the Loopback interface on the RPM, enter the keyword loopback then a number from 0 to
16383.
• For a port channel, enter the keywords port-channel then a number from 1 to 255.
• For a 10-Gigabit Ethernet interface, enter the keyword TenGigabitEthernet then the slot/port
information.
• For a 40-Gigabit Ethernet interface, enter the keyword FortyGigabitEthernet then the slot/
port information.
486 Intermediate System to Intermediate System