Enabling IS-IS point-to-point over Ethernet

IS-IS Point-to-Point over Ethernet can be configured so that devices that are several hops away can form an IS-IS adjacency. The following task configures two devices, Device A and Device B, for IS-IS point-to-point over Ethernet.

Procedure

On Device A, enter the configure terminal command to access global configuration mode.
```
deviceA# configure terminal
```
Enter the interface ethernet command and specify an interface.
```
deviceA(config)# interface ethernet 1/2
```
Enter the ip router isis command to enable IS-IS for the interface.
```
deviceA(conf-if-eth-1/2)# ip router isis
```
Enter the ip address command and specify an IP address and mask to configure a primary IP address for the interface.
```
deviceA(conf-if-eth-1/2)# ip address 10.10.1.1/31
```
Enter the isis point-to-point command to configure IS-IS point-to-point for the Ethernet interface.
```
deviceA(conf-if-eth-1/2)# isis point-to-point
```
On Device B, enter the configure terminal command to access global configuration mode.
```
deviceB# configure terminal
```
Enter the interface ethernet command and specify an interface.
```
deviceB(config)# interface ethernet 2/1
```
Enter the ip router isis command to enable IS-IS for the interface.
```
deviceB(conf-if-eth-2/1)# ip router isis
```
Enter the ip address command and specify an IP address and mask to configure a primary IP address for the interface.
```
deviceB(conf-if-eth-2/1)# ip address 10.10.1.2/31
```
Enter the isis point-to-point command to configure IS-IS point-to-point for the Ethernet interface.
```
deviceB(conf-if-eth-2/1)# isis point-to-point
```

Example

The following example configures two devices, Device A and Device B, for IS-IS point-to-point over Ethernet.

deviceA# configure terminal
deviceA(config)# interface ethernet 1/2
deviceA(conf-if-eth-1/2)# ip router isis
deviceA(conf-if-eth-1/2)# ip address 10.10.1.1/31
deviceA(conf-if-eth-1/2)# isis point-to-point


deviceB# configure terminal
deviceB(config)# interface ethernet 2/1
deviceB(conf-if-eth-2/1)# ip router isis
deviceB(conf-if-eth-2/1)# ip address 10.10.1.2/31
deviceB(conf-if-eth-2/1)# isis point-to-point