Enabling advertisement of a default route

You can enable the device to advertise a default route to all neighboring ISs. The following task enables the advertisement of a default route.

About this task

Procedure

Enter the configure terminal command to access global configuration mode.
```
device# configure terminal
```
Enter the router isis command to enter IS-IS router configuration mode and enable IS-IS on the device.
```
device(config)# router isis
```
Enter the address-family ipv4 unicast command to enable ISIS address-family IPv4 unicast configuration mode.
```
device(config-isis-router)# address-family ipv4 unicast
```
Enter the default-information-originate command to enable the advertisement of a default route.
```
device(config-router-isis-ipv4u)# default-information-originate
```

Example

The following example enables the advertisement of a default route.

device# configure terminal
device(config)# router isis
device(config-isis-router)# address-family ipv4 unicast
device(config-router-isis-ipv4u)# default-information-originate