Configuring Dynamic BFD for CR-LSPs
Pre-configuration Tasks
Compared with static BFD for CR-LSPs, dynamic BFD for CR-LSPs simplifies the configuration and reduces manual operations.
- Configure a static MPLS TE tunnel. For details, see Configuring a Static MPLS TE Tunnel.
- Configure a dynamic MPLS TE tunnel. For details, see Configuring a Dynamic MPLS TE Tunnel.
- Configure a static DS-TE tunnel. For details, see Configuring a Static DS-TE Tunnel.
- Configure a dynamic DS-TE tunnel. For details, see Configuring a Dynamic DS-TE Tunnel.
- Configure CR-LSP backup. For details, see Configuring CR-LSP Backup.
Enabling the Capability of Dynamically Creating BFD Sessions on the Ingress
Context
Enabling the capability of dynamically creating BFD sessions on a TE tunnel can be implemented in either of the following methods:
Enabling MPLS TE BFD Globally when BFD sessions need to be created automatically on a large number of TE tunnels of the ingress node
Enabling MPLS TE BFD on the Tunnel Interface when BFD sessions need to be created automatically on a small number of TE tunnels of the ingress node
Perform the following configurations on the ingress node of an MPLS TE tunnel.
Enabling the Capability of Passively Creating BFD Sessions on the Egress
Context
On a unidirectional LSP, creating a BFD session on the active role (ingress node) triggers the sending of LSP ping request messages to the passive role (egress node). Only after the passive role receives the ping packets, a BFD session can be automatically set up.
Perform the following configurations on the egress node of an MPLS TE tunnel.
Procedure
- Run system-view
The system view is displayed.
- Run bfd
The BFD view is displayed.
- Run mpls-passive
The capability of passively creating BFD sessions is enabled.
After this command is run, a BFD session can be created only after the egress receives an LSP Ping request containing a BFD TLV from the ingress.
(Optional) Adjusting BFD Parameters
Context
BFD parameters are adjusted on the ingress node of a TE tunnel using either of the following modes:
Adjusting Global BFD Parameters when a large number of TE tunnels on the ingress node use the same BFD parameters
Adjusting BFD Parameters on an Interface when certain TE tunnels on the ingress node need to use BFD parameters different from global BFD parameters
Actual local sending interval = MAX { Configured local sending interval, Configured remote receiving interval }
Actual local receiving interval = MAX { Configured remote sending interval, Configured local receiving interval }
Actual local detection interval = Actual local receiving interval x Configured remote detection multiplier
On the egress node of the TE tunnel enabled with the capability of passively creating BFD sessions, the default values of the receiving interval, sending interval and detection multiplier cannot be adjusted. The default values of these three parameters are the minimum configurable values on the egress node. Therefore, the BFD detection interval on the ingress and that on the egress node of a CR-LSP are as follows:
Actual detection interval on the ingress = Configured receiving interval on the ingress node x 3
Actual detection interval on the egress = Configured sending interval on the ingress x Configured detection multiplier on the ingress node
Perform the following configurations on the ingress node of an MPLS TE tunnel.
Verifying the Configuration of Dynamic BFD for CR-LSPs
Procedure
- Run the display bfd configuration dynamic [ verbose ] command to check the configuration of dynamic BFD on the ingress.
- Run the display bfd configuration passive-dynamic [ peer-ip peer-ip remote-discriminator discriminator ] [ verbose ] command to check the configuration of dynamic BFD on the egress.
- Run the display bfd session dynamic [ verbose ] command to check information about the BFD session on the ingress.
- Run the display bfd session passive-dynamic [ peer-ip peer-ip remote-discriminator remote-discr-value ] [ verbose ] command to check information about the BFD session passively created on the egress.
- Check the BFD statistics.
- Run the display bfd statistics command to check statistics about all BFD sessions.
- Run the display bfd statistics session dynamic command to check statistics about dynamic BFD sessions.
- Run the display mpls bfd session [ fec fec-address | monitor | nexthop ip-address | outgoing-interface interface-type interface-number | statistics | verbose ] or display mpls bfd session protocol { cr-static | rsvp-te } [ lsp-id ingress-lsr-id session-id lsp-id [ verbose ] ] command to check information about BFD sessions.