7.6 Integrated IS-IS Operation in a WAN Environment  
  7.6.2 Configuring Integrated IS-IS in a WAN environment  
To enable IS-IS over switched WAN media, do the following:
  • Start the IS-IS process and assign NETs as usual
  • On each NBMA interface issue the following:
    • Design a mesh between the NBMA peers, whether full or partial.
    • Configure point-to-point subinterfaces for each NBMA VC and assign IP addresses.
    • Define the mapping of network protocols and addresses to the VC. If manual mappings are used, for example, x25 map, frame-relay map, then the CLNS mapping must specify broadcast. This is to support routing updates. However, the IP mapping does not require this. It is used only for next-hop resolution.
    • Start IS-IS processing on the subinterface  with the ip router isis command. This command must not be used on the main interface or that multipoint interface will generate a pseudonode LSP for itself.
  • Use integrated IS-IS timer and blocking command to control flooding of link-state information. Use Integrated IS-IS timer and blocking commands.

To illustrate IS-IS configuration in a WAN environment, this IS-IS module ends with a Frame Relay point-to-point scenario and a Frame Relay point-to-multipoint scenario.