(Optional) Configuring IS-IS Attributes on Interfaces of Different Network Types (IPv4)

Different IS-IS attributes can be configured for different types of network interfaces.

Context

The establishment mode of IS-IS neighbor relationships on a broadcast network is different from that on a P2P network. Different IS-IS attributes can be configured for interfaces on different types of networks.

IS-IS is required to select a DIS on a broadcast network. Configure the DIS priorities of IS-IS interfaces so that the interface with the highest priority is selected as the DIS.

The network types of the IS-IS interfaces on both ends of a link must be the same, otherwise, the IS-IS neighbor relationship cannot be established between the two interfaces. If the type of an interface on the neighbor is P2P, you can configure the interface type on the local device to P2P so that an IS-IS neighbor relationship can be established between the two devices.

IS-IS on a P2P network is not required to select a DIS. Therefore, you do not need to configure DIS priorities. To ensure the reliability of P2P links, configure IS-IS to use the three-way handshake mode for IS-IS neighbor relationship establishment so that faults on a unidirectional link can be detected.

Procedure

Configure the DIS priority of an IS-IS interface.
1. Run system-view
  The system view is displayed.
2. Run interface interface-type interface-number
  The interface view is displayed.
3. Run isis dis-priority priority [ level-1 | level-2 ]
  The DIS priority is configured on the interface. The greater the value, the higher the priority.
4. (Optional) Run isis dis-name symbolic-name
  A name is configured for the DIS to facilitate maintenance and management.
5. Run commit
  The configuration is committed.
Configure the network type of an IS-IS interface.
1. Run system-view
  The system view is displayed.
2. Run interface interface-type interface-number
  The interface view is displayed.
3. Run isis circuit-type p2p
  The network type of the interface is set to P2P.
  When the network type of an IS-IS interface changes, interface configurations change accordingly.
  - After a broadcast interface is configured as a P2P interface using the isis circuit-type p2p command, the default values of the interval at which Hello packets are sent, the number of Hello packets that IS-IS fails to receive from a neighbor before declaring the neighbor Down, the interval LSPs are retransmitted on a P2P link, and various IS-IS authentication modes take effect. Consequently, other configurations such as the DIS priority, DIS name, and interval at which CSNPs are sent on a broadcast network become invalid.
  - After the undo isis circuit-type command is run to restore the network type, the default values of the interval at which Hello packets are sent, the number of Hello packets that IS-IS fails to receive from a neighbor before declaring the neighbor. Down, the interval LSPs are retransmitted on a P2P link, the IS-IS authentication mode, the DIS priority, and the interval at which CSNPs are sent on a broadcast network take effect.
4. Run commit
  The configuration is committed.
Configure the scale of the Hello packets sent on the IS-IS interface.
1. Run system-view
  The system view is displayed.
2. Run interface interface-type interface-number
  The interface view is displayed.
  
  3 and 4 are mutually exclusive. Run the command as needed.
3. Run isis small-hello
  The interface is configured to send Hello packets without the padding field.
4. Run isis padding-hello
  The interface is configured to send standard Hello packets with the padding field.
5. Run commit
  The configuration is committed.
Prevent IS-IS from checking whether the IP addresses of received Hello packets are on the same network segment.
1. Run system-view
  The system view is displayed.
2. Run interface interface-type interface-number
  The interface view is displayed.
3. Run isis peer-ip-ignore
  IS-IS is prevented from checking whether the IP addresses of received Hello packets are on the same network segment.
4. Run commit
  The configuration is committed.