(Optional) Configuring a Device to Check the Inbound Interface of a Static CR-LSP

A device uses the static CR-LSP's source interface check function to check whether the inbound interface of labeled packets is the same as that of a configured static CR-LSP. If the inbound interfaces match, the device forwards the packets. If the inbound interfaces do not match, the device discards the packets.

Context

A static CR-LSP is established using manually configured forwarding and resource information. Signaling protocols and path calculation are not used during the setup of CR-LSPs. Setting up a static CR-LSP consumes few resources because the two ends of the CR-LSP do not need to exchange MPLS control packets. The static CR-LSP cannot be adjusted dynamically in a changeable network topology. A static CR-LSP configuration error may cause protocol packets of different NEs and statuses interfere one another, which adversely affects services. To address the preceding problem, a device can be enabled to check source interfaces of static CR-LSPs. With this function configured, the device can only forward packets if both labels and inbound interfaces are correct.

Procedure

Perform the following steps on the P node of a static CR-LSP:
1. Run system-view
  The system view is displayed.
2. Run mpls
  The MPLS view is displayed.
3. Run mpls te
  MPLS TE is globally enabled.
4. Run quit
  The system view is displayed.
5. Run static-cr-lsp transit lsp-name incoming-interface interface-type interface-number in-label in-label outgoing-interface interface-type interface-number out-label out-label
  An incoming label value, inbound interface name, outgoing label value, and outbound interface name are specified for a static CR-LSP.
6. Run undo static-cr-lsp rpf disable
  The device is enabled to check the inbound interface of the static CR-LSP.To disable the function, run the static-cr-lsp rpf disable command. To enable this function again, run the undo static-cr-lsp rpf disable command.
Perform the following steps on the egress of the static CR-LSP:
1. Run system-view
  The system view is displayed.
2. Run mpls
  The MPLS view is displayed.
3. Run mpls te
  MPLS TE is enabled globally.
4. Run quit
  The system view is displayed.
5. Run static-cr-lsp egress lsp-name incoming-interface interface-type interface-number in-label in-label
  An incoming label and inbound interface are specified for the static CR-LSP.
6. Run undo static-cr-lsp rpf disable
  The device is enabled to check the inbound interface of the static CR-LSP.
  
  To disable the function, run the static-cr-lsp rpf disable command. To enable this function again, run the undo static-cr-lsp rpf disable command.