BFD for RIP configuration example (single-hop echo detection for a directly connected neighbor)
Network requirements
As shown in Figure 11, VLAN-interface 100 of Switch A and Switch C runs RIP process 1. VLAN-interface 200 of Switch A runs RIP process 2. VLAN-interface 300 of Switch C and VLAN-interface 200 and VLAN-interface 300 of Switch B run RIP process 1.
Configure a static route destined for 100.1.1.1/24 and enable static route redistribution into RIP on Switch C. This allows Switch A to learn two routes destined for 100.1.1.1/24 through VLAN-interface 100 and VLAN-interface 200 respectively, and uses the one through VLAN-interface 100.
Enable BFD for RIP on VLAN-interface 100 of Switch A. When the link over VLAN-interface 100 fails, BFD can quickly detect the failure and notify it to RIP. RIP deletes the neighbor relationship and route information learned on VLAN-interface 100. It uses the route destined for 100.1.1.1 24 through VLAN-interface 200.
Figure 11: Network diagram
Configuration procedure
Configure IP addresses for interfaces. (Details not shown.)
Configure basic RIP:
# Configure Switch A.
<SwitchA> system-view [SwitchA] rip 1 [SwitchA-rip-1] version 2 [SwitchA-rip-1] undo summary [SwitchA-rip-1] network 192.168.1.0 [SwitchA-rip-1] quit [SwitchA] interface vlan-interface 100 [SwitchA-Vlan-interface100] rip bfd enable [SwitchA-Vlan-interface100] quit [SwitchA] rip 2 [SwitchA-rip-2] version 2 [SwitchA-rip-2] undo summary [SwitchA-rip-2] network 192.168.2.0 [SwitchA-rip-2] quit
# Configure Switch B.
<SwitchB> system-view [SwitchB] rip 1 [SwitchB-rip-1] version 2 [SwitchB-rip-1] undo summary [SwitchB-rip-1] network 192.168.2.0 [SwitchB-rip-1] network 192.168.3.0 [SwitchB-rip-1] quit
# Configure Switch C.
<SwitchC> system-view [SwitchC] rip 1 [SwitchC-rip-1] version 2 [SwitchC-rip-1] undo summary [SwitchC-rip-1] network 192.168.1.0 [SwitchC-rip-1] network 192.168.3.0 [SwitchC-rip-1] import-route static [SwitchC-rip-1] quit
Configure BFD parameters on VLAN-interface 100 of Switch A.
[SwitchA] bfd echo-source-ip 11.11.11.11 [SwitchA] interface vlan-interface 100 [SwitchA-Vlan-interface100] bfd min-transmit-interval 500 [SwitchA-Vlan-interface100] bfd min-receive-interval 500 [SwitchA-Vlan-interface100] bfd detect-multiplier 7 [SwitchA-Vlan-interface100] quit [SwitchA] quit
Configure a static route on Switch C.
[SwitchC] ip route-static 120.1.1.1 24 null 0
Verifying the configuration
# Display the BFD session information on Switch A.
<SwitchA> display bfd session Total Session Num: 1 Up Session Num: 1 Init Mode: Active IPv4 Session Working Under Echo Mode: LD SourceAddr DestAddr State Holdtime Interface 4 192.168.1.1 192.168.1.2 Up 2000ms Vlan100
# Display RIP routes destined for 120.1.1.0/24 on Switch A.
<SwitchA> display ip routing-table 120.1.1.0 24 verbose
Summary Count : 1
Destination: 120.1.1.0/24
Protocol: RIP Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 1 Preference: 100
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x26000002 LastAs: 0
AttrID: 0xffffffff Neighbor: 192.168.1.2
Flags: 0x1008c OrigNextHop: 192.168.1.2
Label: NULL RealNextHop: 192.168.1.2
BkLabel: NULL BkNextHop: N/A
Tunnel ID: Invalid Interface: Vlan-interface100
BkTunnel ID: Invalid BkInterface: N/A
The output shows that Switch A communicates with Switch C through VLAN-interface 100. Then the link over VLAN-interface 100 fails.
# Display RIP routes destined for 120.1.1.0/24 on Switch A.
<SwitchA> display ip routing-table 120.1.1.0 24 verbose
Summary Count : 1
Destination: 120.1.1.0/24
Protocol: RIP Process ID: 2
SubProtID: 0x1 Age: 04h20m37s
Cost: 1 Preference: 100
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x26000002 LastAs: 0
AttrID: 0xffffffff Neighbor: 192.168.2.2
Flags: 0x1008c OrigNextHop: 192.168.2.2
Label: NULL RealNextHop: 192.168.2.2
BkLabel: NULL BkNextHop: N/A
Tunnel ID: Invalid Interface: Vlan-interface200
BkTunnel ID: Invalid BkInterface: N/A
The output shows that Switch A communicates with Switch C through VLAN-interface 200.