Reference Guide
186 | Bidirectional Forwarding Detection
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Configuring BFD for VLANs
BFD on Dell Force10 systems is a Layer 3 protocol. Therefore, BFD is used with routed VLANs. BFD on
VLANs is analogous to BFD on physical ports. If no routing protocol is enabled, and a remote system fails,
the local system does not remove the connected route until the first failed attempt to send a packet. If BFD
is enabled, the local system removes the route when it stops receiving periodic control packets from the
remote system.
There is one BFD Agent for VLANs and port-channels, which resides on RP2 as opposed to the other
agents which are on the line card. Therefore, the 100 total possible sessions that this agent can maintain is
shared for VLANs and port-channels.
Configuring BFD for VLANs is a two-step process:
1. Enabling BFD globally.
2. Establishing sessions with VLAN neighbors.
Related configuration tasks
• Changing session parameters.
• Disabling BFD for VLANs.
Establishing sessions with VLAN neighbors
To establish a session, BFD must be enabled at interface level on both ends of the link, as shown in
Figure 11-9. The session parameters do not need to match.
Figure 11-9. Establishing Sessions with VLAN Neighbors
To establish a BFD session with a VLAN neighbor:
Step Task Command Syntax Command Mode
1 Establish sessions with a VLAN neighbor. bfd neighbor ip-address INTERFACE VLAN
fnC0043mp
F
TOS(config-if-gi-4/25)# switchport
F
TOS(config-if-gi-4/25)# no shutdown
F
TOS(config-if-gi-4/25)# interface vlan 200
F
TOS(config-if-vl-200)# ip address 2.2.3.1/24
F
TOS(config-if-vl-200)# untagged gigabitethernet 4/25
F
TOS(config-if-vl-200)# no shutdown
F
TOS(config-if-vl-200)# bfd neighbor 2.2.3.2
4/25 2/3
VLAN 200
FTOS(config-if-gi-2/3)# switchport
FTOS(config-if-gi-2/3)# no shutdown
FTOS(config-if-gi-2/3)# interface vlan 200
FTOS(config-if-vl-200)# ip address 2.2.3.2/24
FTOS(config-if-vl-200)# untagged gigabitethernet 2/3
FTOS(config-if-vl-200)# no shutdown
FTOS(config-if-vl-200)# bfd neighbor 2.2.3.2
R1
R2