BFD Operational Commands
BFD Show Commands
The command displays the BFD session information.
| Option | Description |
|---|---|
|
Shows the session information. |
|
Shows detailed information about BFD sessions. |
Example: The output lists BGP neighbor relationships with each peer’s address, remote AS number, state, uptime, and the number of prefixes exchanged.
supervisor@rtbrick.net: cfg> show bgp peer instance default Instance: default Peer Remote AS State Up/Down Time PfxRcvd PfxSent 12.0.4.2 65000 Established 0d:00h:18m:26s 0 16 12:0:5::2 65000 Established 0d:01h:05m:40s 0 16 fe80::7810:21 65000 Established 0d:01h:14m:27s 0 16
Example: The otput shows status of active BFD sessions with session state, and the transmit and receive intervals. All sessions are Up, exchanging BFD packets every 1000 ms with their respective peers.
supervisor@rtbrick.net: cfg> show oam bfd session Peer State Transmit-interval(ms) Receive-interval(ms) 12.1.4.2 Up 1000 1000 12:1:5::2 Up 1000 1000 fe80::7810:21 Up 1000 1000
Example: The output shows the IS-IS neighbor interface is up at Level 1 over a point-to-point link and the adjacency has been established from the specified time and will expire in the specified time (expires).
supervisor@rtbrick.net: cfg> show isis neighbor interface ifl-0/0/0/0 Instance: default Interface System Level State Type Up since Expires ifl-0/0/0/0 1921.6800.1000.00 L1 Up P2P Wed Oct 29 06:17:23 in 18s 28274us
Example: This output shows the ISIS Level-1 adjacency on interface ifl-0/0/0/0 with the specified neighbor which is Up in P2P mode. The session has been established from the specified time with 32 transitions. The BFD event is marked as 1.
supervisor@rtbrick.net: cfg> show isis neighbor interface ifl-0/0/0/0 detail
Instance: default
System: 1921.6800.1000.00, Interface: ifl-0/0/0/0
State: Up, Level:L1, Adjacency type: P2P
Circuit type: L1, Hold time: 30.0s, Expiry time: in 27s 371715us
Local IPv4 address: 10.0.0.0, Remote IPv4 address: 10.0.0.1, Unnumbered: False
Local IPv6 address: fe80::7872:1500:c0:0, Remote IPv6 address: fe80::7869:2500:c0:2
Up since: Wed Oct 29 06:17:23 GMT +0000 2025, Last down reason: BFD down
Last transition: 2025-10-29T06:17:23.517920+0000, Number of transitions: 32
Error counters:
Level mismatch: 0, Area mismatch: 0, System ID: 0, Subnet mismatch: 0
Hold timeout: 4, Neighbor down: 6, Interface down: 0, Admin reset: 0, BFD down: 1
Interface configuration: 0, Area configuration: 0, Other: 0
Example: The output shows two BFD sessions (IPv4 and IPv6) are currently 'Up' with both configured for 100 ms transmit and receive intervals.
supervisor@rtbrick.net: cfg> show oam bfd session Peer State Transmit-interval(ms) Receive-interval(ms) 10.0.0.1 Up 100 100 fe80::7869:2500:c0:2 Up 100 100
Example: The output shows both IPv4 and IPv6 BFD sessions on the interface are Up, using 100 milliseconds transmit/receive intervals and a 200 milliseconds hold time interval.
supervisor@rtbrick.net: cfg> show oam bfd session detail
Peer address: 10.0.0.1, Local address: 10.0.0.0
State: Up, Interface: ifl-0/0/0/0, Instance : default
Local discriminator: 1000, Remote discriminator: 1000
Transmit interval: 100ms, Receive interval: 100ms, Detect time multiplier: 2
Hold interval: 200ms
Diagnostic code: No Diagnostic
Last transition time: 2025-10-29T06:20:33.901256+0000, Flap count: 0
Peer address: fe80::7869:2500:c0:2, Local address: fe80::7872:1500:c0:0
State: Up, Interface: ifl-0/0/0/0, Instance : default
Local discriminator: 1001, Remote discriminator: 1001
Transmit interval: 100ms, Receive interval: 100ms, Detect time multiplier: 2
Hold interval: 200ms
Diagnostic code: No Diagnostic
Last transition time: 2025-10-29T06:20:33.901296+0000, Flap count: 0
Example output for OSPFv2 and OSPFv3 neighbor and the corresponding BFD session.
supervisor@rtbrick.net: cfg> show ospf neighbor interface ifl-0/0/0/11 Instance: default, Address family: ipv4 Address Interface Router Area State Priority DR BDR Uptime Expires 12.0.11.2 ifl-0/0/0/11 182.168.0.20 0.0.0.0 Full 1 12.0.11.2 12.0.11.1 0d:00h:00m:25s 40s Instance: default, Address family: ipv6, Instance ID: 0 Address Interface Router Area State Priority DR BDR Uptime Expires fe80::9810:21 ifl-0/0/0/11 182.168.0.20 0.0.0.0 Full 1 182.168.0.10 182.168.0.20 0d:00h:00m:31s 39s
Example for BFD session associated with OSPFv2 neighbor.
supervisor@rtbrick.net: cfg> show oam bfd session peer 12.0.11.2 Peer State Transmit-interval(ms) Receive-interval(ms) 12.0.11.2 Up 100 100
Detailed view of BFD session associated with OSPFv2 neighbor.
supervisor@rtbrick.net: cfg> show oam bfd session peer 12.0.11.2 detail
Peer address: 12.0.11.2, Local address: 12.0.11.1
State: Up, Interface: ifl-0/0/0/11, Instance : default
Clients: ospfv2
Local discriminator: 1061, Remote discriminator: 2978
Transmit interval: 100ms, Receive interval: 100ms, Detect time multiplier: 3
Hold interval: 300ms
Diagnostic code: No Diagnostic
Last transition time: 2025-11-14T05:35:02.675593+0000, Flap count: 1
Example for BFD session associated with OSPFv3 neighbor.
supervisor@rtbrick.net: cfg> show oam bfd session peer fe80::9810:21 Peer State Transmit-interval(ms) Receive-interval(ms) fe80::9810:21 Up 100 100
Detailed view of BFD session associated with OSPFv3 neighbor.
supervisor@rtbrick.net: cfg> show oam bfd session peer fe80::9810:21 detail
Peer address: fe80::9810:21, Local address: fe80::9810:11
State: Up, Interface: ifl-0/0/0/11, Instance : default
Clients: ospf
Local discriminator: 1067, Remote discriminator: 2985
Transmit interval: 100ms, Receive interval: 100ms, Detect time multiplier: 3
Hold interval: 300ms
Diagnostic code: No Diagnostic
Last transition time: 2025-11-14T05:35:07.606463+0000, Flap count: 1
The following example output shows that the BFD session with peer '12.0.0.2' is Up on interface ifl-0/0/0/0, tracked by the static client, with matching discriminators and stable timers, and has transitioned state times.
supervisor@rtbrick.net: cfg> show oam bfd session peer 12.0.0.2 detail
Peer address: 12.0.0.2, Local address: 12.0.0.1
State: Up, Interface: ifl-0/0/0/0, Instance : -
Clients: static
Local discriminator: 1000, Remote discriminator: 1000
Transmit interval: 500ms, Receive interval: 500ms, Detect time multiplier: 3
Hold interval: 3000ms
Diagnostic code: No Diagnostic
Last transition time: 2025-11-18T10:05:39.586178+0000, Flap count: 8
The following example output shows that the static route 192.168.0.26/32 is installed in both IPv4 unicast and labeled-unicast tables with next hop 12.0.0.2 via ifl-0/0/0/0, with a preference of 2.
supervisor@rtbrick.net: cfg> show route source static prefix 192.168.0.26/32
Flags: & - Imported
Instance: default, AFI: ipv4, SAFI: unicast
Flags Prefix/Label Source Pref Next Hop Outgoing Interface
192.168.0.26/32 static 2 12.0.0.2 ifl-0/0/0/0
Instance: default, AFI: ipv4, SAFI: labeled-unicast
Flags Prefix/Label Source Pref Next Hop Label Outgoing Interface
192.168.0.26/32 static 2 12.0.0.2 - ifl-0/0/0/0
BFD Clear Commands
Syntax
This command resets the existing BFD sessions.
| Option | Description |
|---|---|
|
Without any option, the commands clears all the BFD session details. |
|
Clears the specified BFD session. |
|
Clears BFD session for the specified peer. |
Example commands:
clear oam bfd session clear oam bfd session peer-address <peer-address> local-address <local-address> clear oam bfd session session-name <bfd-session-name>