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To enable Bidirectional Forwarding Detection (BFD) fast-detection on a specific IPV4 unicast destination address prefix and on the forwarding next-hop address, use the address-family ipv4 unicast command in static route configuration mode. To return the router to the default setting, use the no form of this command.
address-family ipv4 unicast address nexthop bfd fast-detect [ minimum interval interval ] [ multiplier multiplier ]
no address-family ipv4 unicast address nexthop bfd fast-detect [ minimum interval interval ] [ multiplier multiplier ]
address |
Specifies the IPv4 unicast destination address and prefix on which to enable BFD fast-detection. |
nexthop |
Specifies the next-hop address on which to enable BFD fast-detection. |
bfd fast-detect |
Enables BFD fast-detection on the specified IPV4 unicast destination address prefix and on the forwarding next-hop address. |
minimum interval interval |
(Optional) Ensures that the next hop is assigned with the same hello interval. Replace interval with a number that specifies the interval in milliseconds. Range is from 10 through 10000. |
multiplier multiplier |
(Optional) Ensures that the next hop is assigned with the same detect multiplier. Replace multiplier with a number that specifies the detect multiplier. Range is from 1 through 10. |
interval: 100
multiplier: 3
Static route configuration mode
Release |
Modification |
---|---|
Release 3.3.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
If the multiplier is changed using the bfd multiplier command, the new parameter is used to update all existing BFD sessions for the protocol (BGP, IS-IS, MPLS-TE, or OSPF).
Task ID |
Operations |
---|---|
static |
read, write |
The following example shows how to enable BFD on a static route. In this example, BFD sessions are established with the next-hop 3.3.3.3 when it becomes reachable.
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router static RP/0/0/CPU0:router (config-static)# address-family ipv4 unicast 2.2.2.0/24 3.3.3.3 bfd fast-detection
Command | Description |
| Enables BFD to detect failures in the path between adjacent forwarding engines. |
| Displays BFD information for a specific location. |
To enter Bidirectional Forwarding Detection (BFD) configuration mode, use the bfd command in global configuration mode. To exit BFD configuration mode and return to global configuration mode, use the no form of this command.
bfd
no bfd
This command has no keywords or arguments.
No default behavior or values
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
When you issue the bfd command in global configuration mode, the CLI prompt changes to “config-bfd,” indicating that you have entered BFD configuration mode. In the following sample output, the question mark (?) online help function displays all the commands available under BFD configuration mode:
RP/0/0/CPU0:router(config)# bfd RP/0/0/CPU0:router(config-bfd)# ? commit Commit the configuration changes to running describe Describe a command without taking real actions do Run an exec command echo Configure BFD echo parameters exit Exit from this submode interface Configure BFD on an interface no Negate a command or set its defaults root Exit to the global configuration mode show Show contents of configuration
Task ID |
Operations |
---|---|
bgp |
read, write |
ospf |
read, write |
isis |
read, write |
mpls-te |
read, write |
The following example shows how to enter BFD configuration mode:
RP/0/0/CPU0:router # configure RP/0/0/CPU0:router(config)# bfd RP/0/0/CPU0:router(config-bfd)#
Command | Description |
| Disables echo mode on a router or on an individual interface or bundle. |
| Enters BFD interface configuration mode, where you can disable echo mode on an interface. |
| Displays BFD information for a specific location. |
To specify the destination address for BFD sessions on bundle member links, use the bfd address-family ipv4 destination command in interface configuration mode. To return to the default, use the no form of this command.
bfd address-family ipv4 destination ip-address
no bfd address-family ipv4 destination ip-address
ip-address |
32-bit IPv4 address in dotted-decimal format (A.B.C.D). |
No destination IPv4 address is configured.
Interface configuration (config-if)
Release |
Modification |
---|---|
Release 4.1.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
This command is supported on bundle interfaces only.
Task ID |
Operations |
---|---|
bundle |
read, write |
The following example specifies the IPv4 address of 10.20.20.1 as the destination address for the BFD session on an Ethernet bundle interface:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# interface Bundle-Ether 1 RP/0/0/CPU0:router(config-if)# bfd address-family ipv4 destination 10.20.20.1
The following example specifies the IPv4 address of 10.20.20.1 as the destination address for the BFD session on a POS bundle interface:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# interface Bundle-POS 1 RP/0/0/CPU0:router(config-if)# bfd address-family ipv4 destination 10.20.20.1
Command | Description |
| Enables IPv4 BFD sessions on bundle member links. |
To enable IPv4 BFD sessions on bundle member links, use the bfd address-family ipv4 fast-detect command in interface configuration mode. To return to the default, use the no form of this command.
bfd address-family ipv4 fast-detect
no bfd address-family ipv4 fast-detect
This command has no keywords or arguments.
BFD sessions are disabled.
Interface configuration (config-if)
Release |
Modification |
---|---|
Release 4.1.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
This command is supported on bundle interfaces only.
Task ID |
Operations |
---|---|
bundle |
read, write |
The following example enables IPv4 BFD sessions on member links of an Ethernet bundle:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# interface Bundle-Ether 1 RP/0/0/CPU0:router(config-if)# bfd address-family ipv4 fast-detect
The following example enables IPv4 BFD sessions on member links of a POS bundle:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# interface Bundle-POS 1 RP/0/0/CPU0:router(config-if)# bfd address-family ipv4 fast-detect
Command | Description |
| Specifies the destination address for BFD sessions on bundle member links. |
To specify the minimum interval for asynchronous mode control packets on IPv4 BFD sessions on bundle member links, use the bfd address-family ipv4 minimum-interval command in interface configuration mode. To return to the default, use the no form of this command.
bfd address-family ipv4 minimum-interval milliseconds
no bfd address-family ipv4 minimum-interval [milliseconds]
milliseconds |
Shortest interval between sending BFD control packets to a neighbor. The range is 15 to 30000 milliseconds.
|
The default is 150 ms.
Interface configuration (config-if)
Release |
Modification |
---|---|
Release 4.1.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
This command is supported on bundle interfaces only.
The BFD minimum interval is used with a configurable multiplier (bfd address-family ipv4 multiplier command) to determine the intervals and failure detection times for both control and echo packets in asynchronous mode on bundle member links.
For example, with a session interval of I and a multiplier of M, the following packet intervals and failure detection times apply for BFD asynchronous mode:
When used with bundled VLANs, the following restrictions apply:
The bfd address-family ipv4 minimum-interval command in bundle interface configuration overrides the minimum intervals specified by the bfd minimum-interval command in other areas of BFD configuration.
Note | When multiple applications share the same BFD session, the application with the most aggressive timer is used locally. Then, the result is negotiated with the peer router. |
Keep the following router-specific rules in mind when configuring the minimum BFD interval:
To calculate the rate for BFD sessions on bundle members running in asynchronous mode without echo:
Asynchronous rate per bundle member = (1000 / Min-interval)
To calculate the rate for BFD sessions on bundle members running in asynchronous mode with echo:
Echo interval = (Min-interval x Multiplier)
Ethernet bundle rate = (1000 / Echo interval) x 64
POS bundle rate = (1000 / Echo interval) x 253
Total bundle rate = Ethernet or POS bundle rate + (Base asynchronous rate x Number of links)
Task ID |
Operations |
---|---|
bundle |
read, write |
The following example specifies that control packets will be sent at a minimum interval of 200 ms for IPv4 BFD sessions on member links of an Ethernet bundle:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# interface Bundle-Ether 1 RP/0/0/CPU0:router(config-if)# bfd address-family ipv4 minimum-interval 200
The following example specifies that control packets will be sent at a minimum interval of 200 ms for IPv4 BFD sessions on member links of a POS bundle:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# interface Bundle-POS 1 RP/0/0/CPU0:router(config-if)# bfd address-family ipv4 minimum-interval 200
Command | Description |
| Specifies the minimum control packet interval for BFD sessions for the corresponding BFD configuration scope. |
| Specifies a number that is used as a multiplier with the minimum interval to determine BFD control and echo packet failure detection times and echo packet transmission intervals for IPv4 BFD sessions on bundle member links. |
To specify a number that is used as a multiplier with the minimum interval to determine BFD control and echo packet failure detection times and echo packet transmission intervals for IPv4 BFD sessions on bundle member links, use the bfd address-family ipv4 multiplier command in interface configuration mode. To return to the default, use the no form of this command.
bfd address-family ipv4 multiplier multiplier
no bfd address-family ipv4 multiplier [multiplier]
multiplier |
Number from 2 to 50.
|
The default multiplier is 3.
Interface configuration (config-if)
Release |
Modification |
---|---|
Release 4.1.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
This command is supported on bundle interfaces only.
The BFD multiplier is used with a configurable minimum interval (bfd address-family ipv4 minimum-interval command) to determine the intervals and failure detection times for both control and echo packets in asynchronous mode on bundle member links.
For example, with a session interval of I and a multiplier of M, the following packet intervals and failure detection times apply for BFD asynchronous mode:
BFD control packet failure detection time. This is the maximum amount of time that can elapse without receipt of a BFD control packet before the session is declared down.
Minimum period between sending of BFD echo packets.
Note | The maximum echo packet interval for BFD on bundle member links is the minimum of either 30 seconds or the asynchronous control packet failure detection time. |
Keep the following router-specific rules in mind when configuring the minimum BFD interval:
To calculate the rate for BFD sessions on bundle members running in asynchronous mode without echo:
Asynchronous rate per bundle member = (1000 / Min-interval)
To calculate the rate for BFD sessions on bundle members running in asynchronous mode with echo:
Echo interval = (Min-interval x Multiplier)
Ethernet bundle rate = (1000 / Echo interval) x 64
POS bundle rate = (1000 / Echo interval) x 253
Total bundle rate = Ethernet or POS bundle rate + (Base asynchronous rate x Number of links)
Task ID |
Operations |
---|---|
bundle |
read, write |
The following example specifies the following packet intervals and failure detection times for IPv4 BFD sessions on member links with asynchronous echo mode on an Ethernet bundle:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# interface Bundle-Ether 1 RP/0/0/CPU0:router(config-if)# bfd address-family ipv4 minimum-interval 200 RP/0/0/CPU0:router(config-if)# bfd address-family ipv4 multiplier 3
The following example specifies the same packet intervals and failure detection times for IPv4 BFD sessions on member links of a POS bundle:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# interface Bundle-POS 1 RP/0/0/CPU0:router(config-if)# bfd address-family ipv4 minimum-interval 200 RP/0/0/CPU0:router(config-if)# bfd address-family ipv4 multiplier 3
Command | Description |
| Specifies the minimum interval for asynchronous mode control packets on IPv4 BFD sessions on bundle member links. |
| Specifies the minimum control packet interval for BFD sessions for the corresponding BFD configuration scope. |
To configure timers to allow for delays in receipt of BFD state change notifications (SCNs) from peers before declaring a link bundle BFD session down for IPv4 BFD sessions on bundle member links, use the bfd address-family ipv4 timers command in interface configuration mode. To return to the default, use the no form of this command.
bfd address-family ipv4 timers [ start | nbr-unconfig ] seconds
no bfd address-family ipv4 timers [ start | nbr-unconfig ] seconds
start seconds |
Number of seconds after startup of a BFD member link session to wait for the expected notification from the BFD peer to be received, so that the session can be declared up. If the SCN is not received after that period of time, the BFD session is declared down. The range is 60 to 3600.
|
||
nbr-unconfig seconds |
Number of seconds to wait after receipt of notification that the BFD configuration has been removed by a BFD neighbor, so that any configuration inconsistency between the BFD peers can be fixed. If the BFD configuration issue is not resolved before the specified timer is reached, the BFD session is declared down. The range is 60 to 3600.
|
No timers are configured.
Interface configuration (config-if)
Release |
Modification |
---|---|
Release 4.1.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
This command is supported on bundle interfaces only.
Task ID |
Operations |
---|---|
bundle |
read, write |
The following example configures a timer for members of the specified Ethernet bundle that allows up to 1 minute (60 seconds) after startup of a BFD member link session to wait for receipt of the expected notification from the BFD peer to declare the session up:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# interface Bundle-Ether 1 RP/0/0/CPU0:router(config-if)# bfd address-family ipv4 timers start 60
The following example configures a timer for members of the specified Ethernet bundle that allows up to 1 minute (60 seconds) to wait after receipt of notification that the BFD configuration has been removed by a BFD neighbor, before declaring a BFD session down:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# interface Bundle-Ether 1 RP/0/0/CPU0:router(config-if)# bfd address-family ipv4 timers nbr-unconfig 60
The following example specifies the same timers for member links of a POS bundle:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# interface Bundle-POS 1 RP/0/0/CPU0:router(config-if)# bfd address-family ipv4 timers start 30 RP/0/0/CPU0:router(config-if)# bfd address-family ipv4 timers nbr-unconfig 60
To enable Bidirectional Forwarding Detection (BFD) to detect failures in the path between adjacent forwarding engines, use the bfd fast-detect command in the appropriate configuration mode. To return the software to the default state in which BFD is not enabled, use the no form of this command.
bfd fast-detect [ disable | ipv4 ]
no bfd fast-detect
disable |
Disables the detection of failures in the path between adjacent forwarding engines for a specified entity, such as a BGP neighbor or OSPF interface.
|
||
ipv4 |
Enables Intermediate System-to-Intermediate System (IS-IS) BFD detection of failures in the path between adjacent forwarding engines.
|
BFD detection of failures in the path between adjacent forwarding engines is disabled.
Neighbor configuration
Session group configuration
Neighbor group configuration
Interface configuration
Interface configuration
Router configuration
Area configuration
Area interface configuration
Interface configuration
Release |
Modification |
---|---|
Release 3.3.0 |
This command was introduced. |
Release 3.4.0 |
The bfd fast-detect command was supported in router PIM interface configuration mode. |
Note | BFD can support multihop for internal and external BGP peers. |
Use the bfd fast-detect command to provide protocol- and media-independent, short-duration failure detection of the path between adjacent forwarding engines, including the interfaces and data links.
BFD must be configured on directly connected neighbors for a BFD session to be established between the neighbors.
When MPLS-TE tunnels are protected by backup tunnels, BFD failure triggers fast reroute on affected tunnels.
In OSPF environments, the setting of the bfd fast-detect command is inherited from the highest-level configuration mode in which the command was configured. From the lowest to the highest configuration modes, the inheritance rules are as follows:
The disable keyword is available in the following modes: BGP configuration, OSPF area configuration, and OSPF area interface configuration. In OSPF environments, the disable option enables you to override the inheritance rules described previously. For example, if you enable BFD in an OSPF area, BFD is enabled on all interfaces in that area. If you do not want BFD running on one of the interfaces in that area, you must specify the bfd fast-detect disable command for that interface only.
To disable BFD or return the software to the default state in which BFD is not enabled in IS-IS router configuration mode and MPLS-TE configuration mode, you must enter the no bfd fast-detect command.
Task ID |
Operations |
---|---|
bgp |
read, write |
isis |
read, write |
mpls-te |
read, write |
ospf |
read, write |
multicast |
read, write |
The following example shows how to configure BFD on a BGP router:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# router bgp 65000 RP/0/0/CPU0:router(config-bgp)# neighbor 192.168.70.24 RP/0/0/CPU0:router(config-bgp-nbr)# remote-as 2 RP/0/0/CPU0:router(config-bgp-nbr)# bfd fast-detect
Command | Description |
| Enables BFD fast-detection on a specific IPV4 unicast destination address prefix and on the forwarding next-hop address. |
| Specifies the minimum control packet interval for BFD sessions for the corresponding BFD configuration scope. |
| Sets the BFD multiplier. |
| Displays BFD information for a specific location. |
To specify the minimum control packet interval for BFD sessions for the corresponding BFD configuration scope, use the bfd minimum-interval command in the appropriate configuration mode. To return the router to the default setting, use the no form of this command.
bfd minimum-interval milliseconds
no bfd minimum-interval [milliseconds]
milliseconds |
Interval between sending BFD hello packets to the neighbor. The range is 15 to 30000 milliseconds. For MPLS-TE, the range is 50 to 200 milliseconds. |
BGP interval: 50 milliseconds
IS-IS interval: 250 milliseconds
OSPF interval: 150 milliseconds
MPLS-TE interval: 50 milliseconds
PIM interval: 150 milliseconds
Router configuration
Interface configuration
MPLS TE configuration
Router configuration
Area configuration
Area interface configuration
Interface configuration
Release |
Modification |
---|---|
Release 3.3.0 |
This command was introduced. |
Release 3.4.0 |
The bfd minimum-interval command was supported in router PIM interface configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
In OSPF environments, the setting of the bfd minimum-interval command is inherited from the highest-level configuration mode in which the command was configured. From the lowest to the highest configuration modes, the inheritance rules are as follows:
If desired, you can override these inheritance rules by explicitly configuring the bfd minimum-interval command for a specific area interface or area.
Note | When multiple applications share the same BFD session, the application with the most aggressive timer wins locally. Then, the result is negotiated with the peer router. |
Keep the following router-specific rules in mind when configuring the minimum BFD interval:
This is calculated as: 1000 / value of the bfd minimum-interval command.
Task ID |
Operations |
---|---|
bgp |
read, write |
isis |
read, write |
mpls-te |
read, write |
ospf |
read, write |
multicast |
read, write |
The following example shows how to set the BFD minimum interval for a BGP routing process:
RP/0/0/CPU0:router(config)# router bgp 6500 RP/0/0/CPU0:router(config-bgp)# bfd minimum-interval 275
Command | Description |
| Enables BFD fast-detection on a specific IPV4 unicast destination address prefix and on the forwarding next-hop address. |
| Enables BFD to detect failures in the path between adjacent forwarding engines. |
| Sets the BFD multiplier. |
| Displays BFD information for a specific location. |
To include specific linecards to host BFD multiple path sessions, use the bfd multipath include location command in the global configuration mode. To remove the configuration, use the no form of this command.
bfd multipath include location node-id
no bfd multipath include location node-id
location node-id |
Configures BFD multipath on the specified location. The node-id variable is mentioned in the rack/slot/module notation. |
No default behavior or values
Release | Modification |
---|---|
Release 4.2.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID | Operation |
---|---|
bgp |
read, write |
ospf |
read, write |
isis |
read, write |
mpls-te |
read, write |
This example shows how to run the bfd multipath include location command on a specific location:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# bfd multipath include location 0/5/CPU0
Command | Description |
| Enters BFD configuration mode. |
| Displays information regarding BFD multipath sessions. |
To set the Bidirectional Forwarding Detection (BFD) multiplier, use the bfd multiplier command in the appropriate configuration mode. To return the router to the default setting, use the no form of this command.
bfd multiplier multiplier
no bfd multiplier [multiplier]
multiplier |
Number of times a packet is missed before BFD declares the neighbor down. The ranges are as follows: |
The default multiplier is 3.
Router configuration
Interface configuration
MPLS-TE configuration
Router configuration
Area configuration
Area interface configuration
Interface configuration
Release |
Modification |
---|---|
Release 3.3.0 |
This command was introduced. |
Release 3.4.0 |
The bfd multiplier command was supported in router PIM interface configuration mode. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
In OSPF environments, the setting of the bfd multiplier command is inherited from the highest-level configuration mode in which the command was configured. From the lowest to the highest configuration modes, the inheritance rules are as follows:
If desired, you can override these inheritance rules by explicitly configuring the bfd multiplier command for a specific area interface or area.
If the multiplier is changed using the bfd multiplier command, the new value is used to update all existing BFD sessions for the protocol (BGP, IS-IS, MPLS-TE, or OSPF).
Task ID |
Operations |
---|---|
bgp |
read, write |
isis |
read, write |
mpls-te |
read, write |
ospf |
read, write |
multicast |
read, write |
The following example shows how to set the BFD multiplier in a BGP routing process:
RP/0/0/CPU0:router(config)# router bgp 65000 RP/0/0/CPU0:router(config-bgp)# bfd multiplier 2
Command | Description |
| Enables BFD fast-detection on a specific IPV4 unicast destination address prefix and on the forwarding next-hop address. |
| Enables BFD to detect failures in the path between adjacent forwarding engines. |
| Specifies the minimum control packet interval for BFD sessions for the corresponding BFD configuration scope. |
| Displays BFD information for a specific location. |
To clear Bidirectional Forwarding Detection (BFD) counters, use the clear bfd counters command in EXEC mode.
clear bfd counters { ipv4 | [ singlehop | ] | [ singlehop | ] | all | label } [packet] [timing] [ interface type interface-path-id ] location node-id
ipv4 |
(Optional) Clears BFD over IPv4 information only. |
||
all |
(Optional) Clears BFD over IPv4 information. |
||
packet |
(Optional) Specifies that packet counters are cleared. |
||
timing |
(Optional) Specifies that timing counters are cleared. |
||
interface |
(Optional) Specifies the interface from which the BFD packet counters are cleared. |
||
type |
Specifies the interface type. For more information, use the question mark ( ? ) online help function. |
||
interface-path-id |
Physical interface or virtual interface.
For more information about the syntax for the router, use the question mark ( ? ) online help function. |
||
location node-id |
Clears BFD counters from the specified location. The node-id argument is entered in the rack/slot/module notation. |
The default is the default address family identifier (AFI) that is set by the set default-afi command.
EXEC
Release |
Modification |
---|---|
Release 3.3.0 |
This command was introduced. |
Release 3.7.0 |
The ipv4, ipv6, and all keywords were added. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
For the interface-path-id argument, use the following guidelines:
Task ID |
Operations |
---|---|
bgp |
read, write |
ospf |
read, write |
isis |
read, write |
mpls-te |
read, write |
The following example shows how to clear the BFD IPv4 timing counters:
RP/0/0/CPU0:router# clear bfd counters ipv4 timing location 0/5/cpu0
Command | Description |
| Enables BFD to detect failures in the path between adjacent forwarding engines. |
| Specifies the minimum control packet interval for BFD sessions for the corresponding BFD configuration scope. |
| Sets the BFD multiplier. |
| Displays BFD information for a specific location. |
To specify delays for BFD session startup, use the dampening command in Bidirectional Forwarding Detection (BFD) configuration mode. To return to the default, use the no form of this command.
dampening [bundle-member] { initial-wait | maximum-wait | secondary-wait } milliseconds
no dampening [bundle-member] { initial-wait | maximum-wait | secondary-wait } milliseconds
bundle-member |
(Optional) Specifies initial, maximum, or secondary delays in milliseconds for BFD session startup on BFD bundle members. |
||
initial-wait |
Specifies the initial delay in milliseconds before starting a BFD session. For bundle members, the default is 16000. For non-bundle interfaces, the default is 2000. |
||
maximum-wait |
Specifies the maximum delay in milliseconds before starting a BFD session. For bundle members, the default is 600000. For non-bundle interfaces, the default is 12000.
|
||
secondary-wait |
Specifies a secondary delay in milliseconds before starting a BFD session. For bundle members, the default is 20000. For non-bundle interfaces, the default is 5000. |
||
milliseconds |
Number from 1 to 3600000. |
BFD session startup delays are not configured and the default timer is indefinite.
BFD configuration
Release |
Modification |
---|---|
Release 3.9.0 |
This command was introduced. |
Release 4.0.0 |
The bundle-member keyword was added. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
You do not have to configure the BFD startup timers. If you do configure the initial wait startup timer (using the initial-wait keyword), then it must be less than the value of the maximum wait timer.
By default, BFD dampening is applied to all sessions in the following manner:
BFD on bundle member applies dampening, only if the detected failure is specific to layer 3. BFD dampening is not invoked for L1 or L2 failures. BFD is started after Layer 1 and Layer 2 (LACP) is up to prevent a race condition and false triggers. BFD is notified to stop/ignore when L1 or L2 goes down and must be notified to start/resume when L1 or L2 recovers for a given/affected link/member.
BFD applies dampening till the session transitions from up to down state and the session is not removed. Whenever there is a failure detected at L1 or L2 , the bundle manager removes BFD session on a member.
When dampening is removed a syslog message ‘Exponential backoff dampening for BFD session has been cleared for specified BFD session. When/if same session gets created by application(s), only calculated initial wait time will be applied’ is generated. If this is the desired behavior, then dampening can be enabled by configuring the BFD configuration, by using the command bfd dampening bundle-member l3-failure-only.
Task ID |
Operations |
---|---|
bgp |
read, write |
ospf |
read, write |
isis |
read, write |
mpls-te |
read, write |
The following example shows how to configure an initial and maximum delay for BFD session startup on BFD bundle members:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# bfd RP/0/0/CPU0:router(config-bfd)# dampening bundle-member initial-wait 8000 RP/0/0/CPU0:router(config-bfd)# dampening bundle-member maximum-wait 15000
The following example shows how to change the default initial-wait for BFD on a non-bundle interface:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# bfd RP/0/0/CPU0:router(config-bfd)# dampening initial-wait 30000 RP/0/0/CPU0:router(config-bfd)# dampening maximum-wait 35000
Command | Description |
| Enters BFD configuration mode. |
To disable echo mode on a router or on an individual interface or bundle, use the echo disable command in Bidirectional Forwarding Detection (BFD) configuration mode. To return the router to the default configuration where echo mode is enabled, use the no form of this command.
echo disable
no echo disable
This command has no keywords or arguments.
No default behavior or values
BFD configuration
BFD interface configuration
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
If you are using BFD with Unicast Reverse Path Forwarding (uRPF), you need to use the echo disable command to disable echo mode; otherwise, echo packets are rejected.
Note | To enable or disable IPv4 uRPF checking on an IPv4 interface, use the [no] ipv4 verify unicast source reachable-via command in interface configuration mode. |
Task ID |
Operations |
---|---|
bgp |
read, write |
ospf |
read, write |
isis |
read, write |
mpls-te |
read, write |
The following example shows how to disable echo mode on a router:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# bfd RP/0/0/CPU0:router(config-bfd)# echo disable
The following example shows how to disable echo mode on an individual interface:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# bfd RP/0/0/CPU0:router(config-bfd)# interface gigabitethernet 0/1/0/0 RP/0/0/CPU0:router(config-bfd-if)# echo disable
Command |
Description |
---|---|
Enters BFD configuration mode. |
|
Enters BFD interface configuration mode. |
|
ipv4 verify unicast source reachable-via |
Enables and disables IPv4 uRPF checking on an IPv4 interface. |
Displays BFD information. |
To specify the IP address that you want to use as the source address for BFD echo packets, use the echo ipv4 source command in BFD or BFD interface configuration mode. To return to the default, use the no form of this command.
echo ipv4 source ip-address
no echo ipv4 source ip-address
ip-address |
32-bit IPv4 address in dotted-decimal format (A.B.C.D). |
The IP address of the output interface, or the IP address in the router-id command (if configured), is the default address used for an echo packet when the echo ipv4 source command is not configured.
BFD configuration
BFD interface configuration
Release |
Modification |
---|---|
Release 3.9.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
If you do not configure the IPv4 source address for echo packets, then BFD uses the IP address of the output interface or the address in the router-id command if specified.
You can override the default address for BFD echo packets by specifying an IPv4 source address for echo packets globally for all BFD sessions on the router and at an individual interface. Specifying the IP address at an individual interface will override any value specified globally for BFD on the router.
Task ID |
Operations |
---|---|
bgp |
read, write |
ospf |
read, write |
isis |
read, write |
mpls-te |
read, write |
The following example shows how to specify the IP address 10.10.10.1 as the source address for BFD echo packets for all BFD sessions on the router:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# bfd RP/0/0/CPU0:router(config-bfd)# echo ipv4 source 10.10.10.1
The following example shows how to specify the IP address 10.10.10.1 as the source address for BFD echo packets on an individual Gigabit Ethernet interface:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# bfd RP/0/0/CPU0:router(config-bfd)# interface gigabitethernet 0/1/0/0 RP/0/0/CPU0:router(config-bfd-if)# echo ipv4 source 10.10.10.1
The following example shows how to specify the IP address 10.10.10.1 as the source address for BFD echo packets on an individual Packet-over-SONET (POS) interface:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# bfd RP/0/0/CPU0:router(config-bfd)# interface pos 0/1/0/0 RP/0/0/CPU0:router(config-bfd-if)# echo ipv4 source 10.10.10.1
Command | Description |
| Enters BFD configuration mode. |
| Disables echo mode on a router or on an individual interface or bundle. |
To enable latency detection for BFD echo packets, use the echo latency detect command in BFD configuration mode. To return to the default, use the no form of this command.
echo latency detect [ percentage percent-value [ count packet-count ] ]
no echo latency detect [ percentage percent-value [ count packet-count ] ]
percentage percent-value |
(Optional) Percentage of the echo failure detection time to be detected as bad latency. The range is 100 to 250. The default is 100. |
count packet-count |
(Optional) Number of consecutive packets received with the detected bad latency that will take down a BFD session. The range is 1 to 10. The default is 1. |
Echo latency detection is disabled.
BFD configuration
Release | Modification |
---|---|
Release 4.0.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Note | Latency detection is only valid where echo mode is supported for BFD. However, it is not supported on bundle interfaces. |
Without latency detection, standard BFD echo failure detection tracks only the absence of receipt of echo packets within a period of time based on a counter. However, this standard echo failure detection does not address latency between transmission and receipt of any specific echo packet, which can build beyond desired tolerances over the course of the BFD session.
When latency detection is enabled, a percentage is multiplied to the echo failure detection value (I x M x %), and the roundtrip delay is computed for the echo packet. If this delay is greater than (I x M x %), then the BFD session is taken down.
If you have specified a packet count, then the system tracks the number of packets received back-to-back with bad latency before taking down the session.
Task ID |
Operations |
---|---|
bgp |
read, write |
ospf |
read, write |
isis |
read, write |
mpls-te |
read, write |
In the following examples, consider that the BFD minimum interval is 50 ms, and the multiplier is 3 for the BFD session.
The following example shows how to enable echo latency detection using the default values of 100% of the echo failure period (I x M) for a packet count of 1. In this example, when one echo packet is detected with a roundtrip delay greater than 150 ms, the session is taken down:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# bfd RP/0/0/CPU0:router(config-bfd)# echo latency detect
The following example shows how to enable echo latency detection based on 200% (two times) of the echo failure period for a packet count of 1. In this example, when one packet is detected with a roundtrip delay greater than 300 ms, the session is taken down:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# bfd RP/0/0/CPU0:router(config-bfd)# echo latency detect percentage 200
The following example shows how to enable echo latency detection based on 100% of the echo failure period for a packet count of 3. In this example, when three consecutive echo packets are detected with a roundtrip delay greater than 150 ms, the session is taken down:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# bfd RP/0/0/CPU0:router(config-bfd)# echo latency detect percentage 100 count 3
Command | Description |
| Enters BFD configuration mode. |
| Specifies the minimum control packet interval for BFD sessions for the corresponding BFD configuration scope. |
| Sets the BFD multiplier. |
| Enables verification of the echo packet path before starting a BFD session. |
To enable verification of the echo packet path before starting a BFD session, use the echo startup validate command in BFD configuration mode. To return to the default, use the no form of this command.
echo startup [force]
no echo startup [force]
force |
(Optional) Ignores the remote 'Required Min Echo RX Interval' setting. |
Echo startup validation is disabled.
BFD configuration
Release |
Modification |
---|---|
Release 4.0.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Note | Echo validation is only valid where echo mode is supported for BFD. However, it is not supported on bundle interfaces. |
When a BFD session is down and the echo startup validate command is configured, an echo packet is periodically transmitted on the link while it is down to verify successful transmission within the configured latency before allowing the BFD session to change state.
Without the force option, the echo validation test only runs if the last received control packet contains a non-zero “Required Min Echo RX Interval” value. When the force keyword is configured, the echo validation test runs regardless of this value.
Task ID |
Operations |
---|---|
bgp |
read, write |
ospf |
read, write |
isis |
read, write |
mpls-te |
read, write |
The following example shows how to enable echo startup validation for BFD sessions on non-bundle interfaces if the last received control packet contains a non-zero “Required Min Echo RX Interval” value:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# bfd RP/0/0/CPU0:router(config-bfd)# echo startup validate
The following example shows how to enable echo startup validation for BFD sessions on non-bundle interfaces regardless of the “Required Min Echo RX Interval” value in the last control packet:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# bfd RP/0/0/CPU0:router(config-bfd)# echo startup validate force
Command | Description |
| Enters BFD configuration mode. |
| Enables latency detection for BFD echo packets. |
To enter Bidirectional Forwarding Detection (BFD) interface configuration mode, where you can disable echo mode on an interface, use the interface command in BFD configuration mode. To return to BFD configuration mode, use the no form of this command.
interface type interface-path-id
no interface type interface-path-id
type |
Interface type. For more information, use the question mark (?) online help function. |
||
interface-path-id |
Physical interface or virtual interface.
For more information about the syntax for the router, use the question mark (?) online help function. |
No default behavior or values
BFD configuration
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
For the interface-path-id argument, use the following guidelines:
If you are using BFD with Unicast Reverse Path Forwarding (uRPF) on a particular interface, then you need to use the echo disable command in BFD interface configuration mode to disable echo mode on that interface; otherwise, echo packets are rejected by the interface.
Note | To enable or disable IPv4 uRPF checking on an IPv4 interface, use the [no] ipv4 verify unicast source reachable-via command in interface configuration mode. |
Task ID |
Operations |
---|---|
bgp |
read, write |
ospf |
read, write |
isis |
read, write |
mpls-te |
read, write |
The following example shows how to enter BFD interface configuration mode for a Gigabit Ethernet interface:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# bfd RP/0/0/CPU0:router(config-bfd)# interface gigabitethernet 0/1/0/0 RP/0/0/CPU0:router(config-bfd-if)#
The following example shows how to enter BFD interface configuration mode for a Packet-over-SONET/SDH (POS) interface:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# bfd RP/0/0/CPU0:router(config-bfd)# interface pos 0/1/0/0 RP/0/0/CPU0:router(config-bfd-if)#
Command |
Description |
---|---|
Enters BFD configuration mode. |
|
Disables echo mode on an individual interface or on the entire router. |
|
ipv4 verify unicast source reachable-via |
Enables and disables IPv4 uRPF checking on an IPv4 interface. |
Displays BFD information. |
To specify the maximum time to live (TTL) value for multihop sessions per system, use the multihop ttl-drop-threshold command in the BFD configuration mode. To return to the default, use the no form of this command.
multihop ttl-drop-threshold value
no multihop ttl-drop-threshold value
value |
Specifies the configurable range of values for TTL. It ranges from 0 to 254. |
No default behavior or values
BFD configuration
Release | Modification |
---|---|
Release 4.2.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
If the TTL of a BFD packet received on the router is less than the configured ttl-drop-threshold, the packet will be dropped. If the TTL of a BFD packet received on the router is greater than or equal to the configured ttl-drop-threshold, the packet will be processed.
Note | This configuration command is only applicable for BFD multihop sessions. |
Task ID | Operation |
---|---|
bgp |
read, write |
ospf |
read, write |
isis |
read, write |
mpls-te |
read, write |
This example shows how to set the maximum TTL value as 2 using the multihop ttl-drop-threshold command:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# bfd multihop ttl-drop-threshold 2
Command | Description |
| Displays BFD counter information. |
| Displays information regarding BFD multipath sessions. |
To display Bidirectional Forwarding Detection (BFD) information for a specific location, use the show bfd command in EXEC mode.
show bfd [ ipv4 | [ singlehop | ] | all |label ] interface [ destination | ] [ location node-id ]
ipv4 |
(Optional) Displays BFD over IPv4 information only. |
all |
(Optional) Displays BFD over IPv4 information. |
label |
(Optional) Displays the BFD label information. |
interface |
Specifies the BFD interface. |
destination |
(Optional) Specifies the destination IPv4 unicast address. |
source |
(Optional) Specifies the source IPv4 unicast address. |
location node-id |
Displays BFD information for the specified location. The node-id argument is entered in the rack/slot/module notation. |
The default is the default address family identifier (AFI) that is set by the set default-afi command.
EXEC
Release |
Modification |
---|---|
Release 3.3.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
bgp |
read |
ospf |
read |
isis |
read |
mpls-te |
read |
The following example shows the output from the show bfd command:
RP/0/0/CPU0:router# show bfd
IPV4 Sessions Up: 0, Down: 0, Total: 0
The following example shows the output from the show bfd all command:
RP/0/0/CPU0:router# show bfd all
IPv4:
-----
IPV4 Sessions Up: 20, Down: 0, Unknown/Retry: 2, Total: 22
IPv6:
-----
IPV6 Sessions Up: 128, Down: 2, Unknown/Retry: 1, Total: 131
Label:
-----
Label Sessions Up: 10, Down: 0, Unknown/Retry: 1, Total: 11
The following example shows the output from the show bfd ipv4 command:
RP/0/0/CPU0:router# show bfd ipv4
IPV4 Sessions Up: 0, Down: 0, Total: 0
The following example shows the output from the show bfd ipv4 location command:
RP/0/0/CPU0:router# show bfd ipv6 session detail interface tenGigE 0/0/0/0.100
I/f: TenGigE0/0/0/0.100, Location: 0/0/CPU0
Dest: 1001:1:1:1:1:1:1:2
Src: 1001:1:1:1:1:1:1:1
State: UP for 0d:1h:37m:3s, number of times UP: 1
Session type: PR/V6/SH
Received parameters:
Version: 1, desired tx interval: 300 ms, required rx interval: 300 ms
Required echo rx interval: 0 us, multiplier: 3, diag: None
My discr: 2148076695, your discr: 2148075550, state UP, D/F/P/C/A: 0/0/0/1/0
Transmitted parameters:
Version: 1, desired tx interval: 300 ms, required rx interval: 300 ms
Required echo rx interval: 0 us, multiplier: 3, diag: None
My discr: 2148075550, your discr: 2148076695, state UP, D/F/P/C/A: 0/1/0/1/0
Timer Values:
Local negotiated async tx interval: 300 ms
Remote negotiated async tx interval: 300 ms
Desired echo tx interval: 0 s, local negotiated echo tx interval: 0 us
Echo detection time: 0 us(0 us*3), async detection time: 900 ms(300 ms*3)
Local Stats:
Intervals between async packets:
Tx: Number of intervals=3, min=10 ms, max=2290 ms, avg=824 ms
Last packet transmitted 5823 s ago
Rx: Number of intervals=6, min=3 ms, max=2 s, avg=461 ms
Last packet received 5823 s ago
Intervals between echo packets:
Tx: Number of intervals=0, min=0 s, max=0 s, avg=0 s
Last packet transmitted 0 s ago
Rx: Number of intervals=0, min=0 s, max=0 s, avg=0 s
Last packet received 0 s ago
Latency of echo packets (time between tx and rx):
Number of packets: 0, min=0 us, max=0 us, avg=0 us
Session owner information:
Desired Adjusted
Client Interval Multiplier Interval Multiplier
-------------------- --------------------- ---------------------
ipv6_static 300 ms 3 300 ms 3
ipv6_static 300 ms 3 300 ms 3
H/W Offload Info:
H/W Offload capability : Y, Hosted NPU : 0/0/CPU0/NPU0
Async Offloaded : Y, Echo Offloaded : N
Async rx/tx : 7/4
Platform Info:
NPU ID: 0
Async RTC ID : 1 Echo RTC ID : 0
Async Feature Mask : 0x8 Echo Feature Mask : 0x0
Async Session ID : 0x3c07 Echo Session ID : 0x0
Async Tx Key : 0x3c070801 Echo Tx Key : 0x0
Async Tx Stats addr : 0x3f69e800 Echo Tx Stats addr : 0x0
Async Rx Stats addr : 0x4069e800 Echo Rx Stats addr : 0x0
Command | Description |
| Enables BFD to detect failures in the path between adjacent forwarding engines. |
| Specifies the minimum control packet interval for BFD sessions for the corresponding BFD configuration scope. |
| Sets the BFD multiplier. |
To display Bidirectional Forwarding Detection (BFD) client information, use the show bfd client command in EXEC mode.
show bfd client [detail]
detail |
(Optional) Specifies detailed client information including number of sessions and client reconnects. |
Enter the show bfd client command without specifying the detail keyword to display summarized BFD client information.
EXEC
Release |
Modification |
---|---|
Release 3.3.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
bgp |
read |
ospf |
read |
isis |
read |
mpls-te |
read |
The following example shows the output from the show bfd client command:
RP/0/0/CPU0:router# show bfd client Name Node Num sessions --------------- ---------- -------------- bgp 0/0/CPU0 0 isis 0/0/CPU0 0 isis 0/0/CPU0 0
Field |
Description |
---|---|
Name |
Name of the BFD client. |
Node |
Location of the BFD client. |
Num sessions |
Number of active sessions for the BFD client. |
Command | Description |
| Enables BFD to detect failures in the path between adjacent forwarding engines. |
| Specifies the minimum control packet interval for BFD sessions for the corresponding BFD configuration scope. |
| Sets the BFD multiplier. |
| Displays BFD information for a specific location. |
To display Bidirectional Forwarding Detection (BFD) counter information, use the show bfd counters command in EXEC mode.
show bfd counters [ ipv4 | [ singlehop | ] | all | label ] packet [ interface type interface-path-id ] location node-id
ipv4 |
(Optional) Displays BFD over IPv4 information only. |
||
all |
(Optional) Displays BFD over IPv4 information. |
||
packet |
Specifies that packet counters are displayed. |
||
interface |
(Optional) Specifies the interface for which to show counters. |
||
type |
Interface type. For more information, use the question mark (?) online help function. |
||
interface-path-id |
Physical interface or virtual interface.
For more information about the syntax for the router, use the question mark (?) online help function. |
||
location node-id |
Displays BFD counters from the specified location. The node-id argument is entered in the rack/slot/module notation. |
The default is the default address family identifier (AFI) that is set by the set default-afi command.
EXEC
Release |
Modification |
---|---|
Release 3.3.0 |
This command was introduced. |
Release 3.7.0 |
The ipv4, ipv6, and all keywords were added. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
For the interface-path-id argument, use the following guidelines:
Task ID |
Operations |
---|---|
bgp |
read |
ospf |
read |
isis |
read |
mpls-te |
read |
RP/0/0/CPU0:router# show bfd counters ipv4 packet
IPv4 Singlehop:
GigabitEthernet0/0/1/2 Recv Xmit Recv Xmit
Async: 4148 4137 Echo: ( 47136) 80192
GigabitEthernet0/1/1/2 Recv Xmit Recv Xmit
Async: 116876 125756 Echo: ( 2268192) 2301312
Bundle-Ether10 Recv Xmit Recv Xmit
Async: 2 0 Echo: 0 0
Bundle-Ether20 Recv Xmit Recv Xmit
Async: 91 0 Echo: 0 0
IPv4 Multihop: (Src IP/Dst IP/Vrf Id)
33.15.151.4/33.16.151.4/0x12345678 Recv Xmit
Async: 0 570337
Field |
Description |
---|---|
Async |
Number of asynchronous mode (control) packets that were received or transmitted on the specified interface. |
Echo |
Number of echo packets that were received or transmitted on the specified interface. |
Command | Description |
| Enables BFD to detect failures in the path between adjacent forwarding engines. |
| Specifies the minimum control packet interval for BFD sessions for the corresponding BFD configuration scope. |
| Sets the BFD multiplier. |
To display IPv4 Bidirectional Forwarding Detection (BFD) MIB session information, use the show bfd mib session command in EXEC mode.
show bfd mib session [ location node-id ]
location node-id |
(Optional) Displays all IPv4 BFD MIB session information stored on the specified node. The node-id argument is entered in the rack/slot/module notation. |
When node-id is not specified, information for all IPv4 BFD MIB sessions, stored on the route processor node, is displayed.
EXEC
Release |
Modification |
---|---|
Release 3.8.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
When node-id is not specified, information for all IPv4 BFD MIB sessions, stored on the route processor node, is displayed, and this information is populated and updated only after SNMP operations for those BFD MIB sessions are performed.
When node-id is specified, information for all IPv4 BFD MIB sessions, stored on the specified node (linecard), is displayed, and this information is updated automatically without SNMP operations being performed.
Task ID |
Operations |
---|---|
bgp |
read |
ospf |
read |
isis |
read |
mpls-te |
read |
The following example displays all IPv4 BFD MIB session information stored on the RP node:
RP/0/0/CPU0:router# show bfd mib session
Tue Sep 9 07:49:30.828 PST DST
Local Discr: 327681(0x50001), Remote Discr: 0(0x0)
BFD session: GigabitEthernet0_1_5_2(0x11800c0), 10.27.4.7
Current State: ADMIN DOWN, Number of Times UP: 0
Running Version: 0, Last Down Diag: None
Last Up Time (s.ns): 0.0
Last Down Time (s.ns): 0.0
Detection Multiplier: 0
Desired Min TX Interval: 0
Required Min RX Interval: 0
Required Min RX Echo Interval: 0
Packets in/out: 0/0
Current Trap Bitmap: 0x0
Last Time Cached: Not yet cached
The following example displays all IPv4 and IPv6 BFD MIB session information stored on 0/1/CPU0:
RP/0/0/CPU0:router# show bfd mib session location 0/1/CPU0
Tue Sep 9 07:44:49.190 PST DST
Local Discr: 327681(0x50001), Remote Discr: 0(0x0)
BFD session: GigabitEthernet0_1_5_2(0x11800c0), 10.27.4.7
Number of times UP: 0
Last Down Diag: None
Last Up Time (s.ns): 0.0
Last Down Time (s.ns): 0.0
Packets in/out: 0/1140134
Field |
Description |
---|---|
date and timestamp |
Date and time stamp during which a snapshot of the BFD MIB session information is taken. |
Local Discr |
Local discriminator (in decimal and hexadecimal) that uniquely identifies the BFD MIB session. |
Remote Discr |
Session discriminator (in decimal and hexadecimal) that was chosen by the remote system for the BFD MIB session. |
BFD session |
Index of interface upon which the BFD MIB session is running. Also, neighboring IP address that is monitored with the BFD MIB session. |
Current State |
Current state of the BFD MIB session. |
Number of Times UP |
Number of times the BFD MIB session has gone into the up state since the router was last rebooted. |
Running Version |
BFD protocol version number in which the BFD MIB session is running. |
Last Down Diag |
Diagnostic value associated with the last time the BFD MIB session went down. |
Last Up Time (s.ns) |
Value of sysUpTime, in seconds.nanoseconds, during which the BFD MIB session last came up. If such an event does not exist, a zero is displayed. |
Last Down Time (s.ns) |
Value of sysUpTime, in seconds.nanoseconds, during which communication was last lost with the neighbor. If such an event does not exist, a zero is displayed. |
Detection Multiplier |
Failure detection multiplier. |
Desired Min TX Interval |
Minimum interval, in microseconds, preferred by the local system when transmitting BFD control packets. |
Required Min RX Interval |
Minimum interval, in microseconds, that the local system supports between received BFD control packets. |
Required Min RX Echo Interval |
Minimum interval, in microseconds, that the local system supports between received BFD echo packets. |
Packets in/out |
Total number of BFD messages received and transmitted for the BFD MIB session. |
Current Trap Bitmap |
Bits that control the trap for the BFD MIB session. A nonzero value indicates that the trap is generated when the next trap event is triggered. |
Last Time Cached |
When information for the BFD MIB session was last cached. Typically, the information is cached when SNMP operations for the BFD MIB session are performed. |
Command | Description |
|
|
To display information concerning only BFD multipath sessions, use the show bfd multipath command in the EXEC mode.
show bfd multipath { ipv4 | ipv6 | label | all } location node-id
ipv4 |
Displays BFD over IPv4 information only. |
ipv6 |
Displays BFD over IPv6 information only. |
label |
Displays BFD label information. |
all |
Displays both BFD over IPv4 and BFD over IPv6 information. |
location node-id |
Displays BFD counters from the specified location. The node-id argument is entered in the rack/slot/module notation. |
No default behavior or values
Release | Modification |
---|---|
Release 4.2.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID | Operation |
---|---|
bgp |
read |
ospf |
read |
isis |
read |
mpls-te |
read |
This example shows the sample output for show bfd multipath command:
RP/0/0/CPU0:routershow bfd multipath location 0/5/cpu0 Int/Src Addr Label/Dest Addr VRF ID Discr Node State --------------- --------------- ---------- ---------- -------- -------- pw-ether 1 10.10.10.10 0x00000002 0x4 0/5/CPU0 DOWN tunnel-ip 1 1.1.1.1 0x8 0x5 0/5/CPU0 UP
To display Bidirectional Forwarding Detection (BFD) session information, use the show bfd session command in EXEC mode.
show bfd [ ipv4 | [ singlehop | ] | ipv6 | [ singlehop | ] | all | label ] session [ interface type interface-path-id [ destination ip-address ] [detail] [in-label] ] location node-id
ipv4 |
(Optional) Displays BFD over IPv4 information only. |
||
all |
(Optional) Displays BFD over IPv4 information. |
||
label |
(Optional) Displays the MPLS Transport Profile (MPLS-TP) label BFD information only. |
||
interface |
(Optional) Specifies the interface for which to show information. |
||
type |
Interface type. For more information, use the question mark (?) online help function. |
||
interface-path-id |
Physical interface or virtual interface.
For more information about the syntax for the router, use the question mark (?) online help function. |
||
destination ip-address |
(Optional) Displays the BFD session destined for the specified IP address. |
||
detail |
(Optional) Displays detailed session information, including statistics and number of state transitions. |
||
in-label |
(Optional) Displays the BFD session with a specific incoming MPLS-TP label. |
||
location node-id |
(Optional) Displays BFD sessions hosted from the specified location. The node-id argument is entered in the rack/slot/module notation. |
The default is the default address family identifier (AFI) that is set by the set default-afi command.
EXEC
Release |
Modification |
---|---|
Release 3.3.0 |
This command was introduced. |
Release 3.7.0 |
The ipv4, ipv6, and all keywords were added. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
For the interface-path-id argument, use the following guidelines:
Note | Only VRF ID is displayed in the summary CLI (such as show bfd multiple-path, show bfd all session, show bfd counters) and VRF name and VRF ID is displayed in the detailed CLI (such as show bfd all session detail, show bfd all session status). |
Task ID |
Operations |
---|---|
bgp |
read |
ospf |
read |
isis |
read |
mpls-te |
read |
The following example shows the output from the show bfd session command with the detail keyword and IPv4 as the default:
RP/0/0/CPU0:router# show bfd session detail
I/f:TenGigE0/2/0/0.6, Location:0/2/CPU0, dest:10.0.6.2, src:10.0.6.1
State:UP for 0d:0h:3m:4s, number of times UP:1
Received parameters:
Version:1, desired tx interval:2 s, required rx interval:2 s
Required echo rx interval:1 ms, multiplier:3, diag:None
My discr:589830, your discr:590028, state UP, D/F/P/C/A:0/0/0/1/0
Transmitted parameters:
Version:1, desired tx interval:2 s, required rx interval:2 s
Required echo rx interval:1 ms, multiplier:3, diag:None
My discr:590028, your discr:589830, state UP, D/F/P/C/A:0/0/0/1/0
Timer Values:
Local negotiated async tx interval:2 s
Remote negotiated async tx interval:2 s
Desired echo tx interval:250 ms, local negotiated echo tx interval:250 ms
Echo detection time:750 ms(250 ms*3), async detection time:6 s(2 s*3)
Local Stats:
Intervals between async packets:
Tx:Number of intervals=100, min=952 ms, max=2001 ms, avg=1835 ms
Last packet transmitted 606 ms ago
Rx:Number of intervals=100, min=1665 ms, max=2001 ms, avg=1828 ms
Last packet received 1302 ms ago
Intervals between echo packets:
Tx:Number of intervals=100, min=250 ms, max=252 ms, avg=250 ms
Last packet transmitted 188 ms ago
Rx:Number of intervals=100, min=250 ms, max=252 ms, avg=250 ms
Last packet received 187 ms ago
Latency of echo packets (time between tx and rx):
Number of packets:100, min=1 ms, max=2 ms, avg=1 ms
Session owner information:
Client Desired interval Multiplier
---------------- -------------------- --------------
bgp- 250 ms 3
The following example shows the output from the show bfd session command with the all keyword, which displays both IPv4 and IPv6 information:
RP/0/0/CPU0:router# show bfd all session location 0/1/CPU0 Mon Nov 5 08:51:50.339 UTC IPv4: ----- Interface Dest Addr Local det time(int*mult) State Echo Async -------------------- --------------- ---------------- ---------------- --------- PO0/1/0/0 10.0.0.2 300ms(100ms*3) 6s(2s*3) UP IPv6: ----- Interface Dest Addr Local det time(int*mult) State Echo Async -------------------- ---------------------------------------------- PO0/1/0/0 abcd::2 0s(0s*0) 15s(5s*3) UP
Command | Description |
| Enables BFD to detect failures in the path between adjacent forwarding engines. |
| Sets the BFD multiplier. |
| Displays BFD MIB session information. |
To display the percentage of PPS rate in use per line card, maximum usage of PPS, and total number of sessions, use the show bfd summary command in the EXEC mode.
show bfd summary [ private ] locationnode-id
private |
Displays the private information. |
location node-id |
Displays BFD counters from the specified location. The node-id argument is entered in the rack/slot/module notation. |
No default behavior or values
Release | Modification |
---|---|
Release 4.2.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID | Operation |
---|---|
bgp |
read |
ospf |
read |
isis |
read |
mpls-te |
read |
This example shows the sample output from the show bfd summary command for a specified location:
RP/0/0/CPU0:routershow bfd summary location 0/1/cpu0
Node PPS rate usage Session number
% Used Max Total Max
---------- --------------- --------------
0/1/CPU0 0 80 9600 4 4000
This example shows the sample output from the show bfd summary command:
RP/0/0/CPU0:routershow bfd summary
Node PPS rate usage Session number
% Used Max Total Max
---------- --------------- --------------
0/0/CPU0 0 0 9600 0 4000
0/1/CPU0 0 0 9600 0 4000
0/2/CPU0 0 0 9600 0 4000
0/5/CPU0 0 0 9600 0 4000
0/6/CPU0 0 0 9600 0 4000
0/7/CPU0 0 0 9600 0 4000