Creating an IPv6 IS-IS Process

Before configuring basic IPv6 IS-IS features, create an IPv6 IS-IS process and then enable IPv6 IS-IS interfaces.

Context

To create an IPv6 IS-IS process, perform the following operations:

Create an IS-IS process, configure a NET for the device, and enable IPv6 for the IS-IS process.
(Optional) Configure the level of a device.

Configure the device level based on the network planning. If no device level is configured, IS-IS establishes separate neighbor relationships for Level-1 and Level-2 devices and maintains two identical LSDBs, consuming excessive system resources.
(Optional) Configure IS-IS host name mapping.

After IS-IS host name mapping is configured, a host name rather than the system ID of a device is displayed when you run a display command. This configuration improves the maintainability on an IS-IS network.
(Optional) Enable IS-IS adjacency strict-check.

If both IPv4 and IPv6 run on a network, and the IPv6 topology type of this network is standard or compatible, enable IS-IS adjacency strict-check to ensure that an IS-IS adjacency is established only when both IPv4 and IPv6 go Up. IS-IS adjacency strict-check improves network reliability and prevents traffic losses.

Procedure

Create an IS-IS process, configure the NET of a device, and enable IPv6 for the process.
1. Run system-view
  The system view is displayed.
2. Run isis [ process-id ]
  An IS-IS process is created, and the IS-IS process view is displayed.
  
  The process-id parameter specifies the ID of an IS-IS process. The default value of process-id is 1. To associate an IS-IS process with a VPN instance, run the isis process-id vpn-instance vpn-instance-name command.
3. Run network-entity net-addr
  A NET is configured.
  NET of IS-IS consists of three parts:
  - Part one is the area ID that is variable (1 to 13 bytes), and the area IDs of the devices in the same area are identical.
  - Part two is the system ID (6 bytes) of this device, which must be unique in the whole area and backbone area.
  - Part three is the last byte "SEL", whose value must be "00".
  For example, the NET of IS-IS device can be configured as 10.1234.6e9f.0001.00.
  An area ID is used to uniquely identify an area in the same IS-IS domain. All routers in the same Level-1 area must share the same area ID, while routers in the same Level-2 area can have different area IDs.
  The system ID must be unique in the whole area and backbone area.
  Multiple NETs can be configured, but they must have the same system ID.
  Configuring loopback interface addresses based on NETs is recommended to ensure that a NET is unique on the network. If NETs are not unique, route flapping will easily occur. System ID used in IS-IS can be obtained in the following way: extend each part of the IP address to 3 bits, add 0 to the front of any part that is shorter than 3 bits, divide the extended address into three parts, with each part consisting of four decimal digits, and the reconstructed address is the system ID.
4. Run ipv6 enable [ topology { compatible [ enable-mt-spf ] | ipv6 | standard } ]
  The IPv6 of IS-IS process is enabled.
5. Run commit
  The configuration is committed.
(Optional) Configure the level of a device.
1. Run is-level { level-1 | level-1-2 | level-2 }
  The level of the router is configured.
2. Run commit
  The configuration is committed.
(Optional) Configure IS-IS host name mapping.
1. Run is-name symbolic-name
  IS-IS dynamic host name mapping is configured. The system ID of the local device is mapped to the specified host name.
  
  The value of symbolic-name is contained in LSP packets and advertised to other IS-IS devices.
  
  symbolic-name rather than the system ID of the local IS-IS device is displayed on another IS-IS device.
2. Run is-name map system-id symbolic-name
  IS-IS static host name mapping is configured. The system ID of a peer IS-IS device is mapped to the specified host name.
  
  This command configuration takes effect only on the local IS-IS device. The value of symbolic-name will not be added to LSP packets.
  
  If dynamic host name mapping is configured on an IS-IS network, the mappings on the network override those configured on the local router.
3. Run commit
  The configuration is committed.
(Optional) Enable IS-IS adjacency strict-check.
1. Run adjacency-strict-check enable
  IS-IS adjacency strict-check is enabled.
2. Run commit
  The configuration is committed.