Board Selection Rules for BFD Sessions

Multi-hop session

The board with the interface that receives BFD negotiation packets is preferentially selected. If the board does not have available BFD resources, a load-balancing integrated board will be selected. If no load-balancing integrated board is available, board selection fails.

Single-hop session bound to a physical interface or its sub-interfaces

If the board on which the bound interface or sub-interfaces reside is BFD-capable in hardware, this board is selected. If the board does not have available BFD resources, board selection fails.

Single-hop session bound to a trunk interface

A board is selected from the boards on which trunk member interfaces reside. If none of the boards has available BFD resources, board selection fails.

If all of these boards are BFD-capable in hardware, one will be selected based on load balancing.

BFD for LDP LSP session

• If an outbound interface is configured for a BFD for LDP LSP session, the board on which the outbound interface resides is preferentially selected.

  • If the outbound interface is a tunnel interface, a board is selected based on multi-hop session rules because tunnel interfaces reside on the IPU that is BFD-incapable in hardware.
  • If the board on which the outbound interface resides is BFD-capable in hardware, this board is selected.
• If a BFD session is not configured with an outbound interface, a board is selected for the BFD session based on multi-hop session rules.

BFD for TE session

Preferentially select the specified board. If no board is specified, select the board based on the multi-hop session principle.

BFD for VLANIF session

• If a single-hop BFD for IP session that is not a Per-Link session is bound to a VLANIF interface, board selection is performed among the physical boards where Eth-Trunk member interfaces reside. If none of the physical boards have resources, board selection fails.
• If a single-hop BFD for IP session that is a Per-Link session is bound to a VLANIF interface, board selection is performed for each of the physical boards where Eth-Trunk member interfaces reside. If the physical board where a member interface resides does not have resources, board selection fails for the corresponding BFD sub-session.