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BFD Commands
- address-family ipv4 unicast (BFD)
- bfd
- bfd address-family ipv4 destination
- bfd address-family ipv4 fast-detect
- bfd address-family ipv4 minimum-interval
- bfd address-family ipv4 multiplier
- bfd address-family ipv4 timers
- bfd fast-detect
- bfd minimum-interval
- bfd multipath include location
- bfd multiplier
- clear bfd counters
- dampening (BFD)
- echo disable
- echo ipv4 source
- echo latency detect
- echo startup validate
- interface (BFD)
- ipv6 checksum
- multihop ttl-drop-threshold
- show bfd
- show bfd client
- show bfd counters
- show bfd mib session
- show bfd multipath
- show bfd session
- show bfd summary
address-family ipv4 unicast (BFD)
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 ]
Syntax Description
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.
Command History
Usage Guidelines
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
Examples
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/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# router static RP/0/RP0/CPU0:router (config-static)# address-family ipv4 unicast 2.2.2.0/24 3.3.3.3 bfd fast-detectionbfd
To enter Bidirectional Forwarding Detection (BFD) configuration mode, use the bfd command in XR Config mode. To exit BFD configuration mode and return to global configuration mode, use the no form of this command.
Command History
Usage Guidelines
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 XR Config 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/RP0/CPU0:router(config)# bfd RP/0/RP0/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 XR Config mode show Show contents of configurationTask ID
Examples
The following example shows how to enter BFD configuration mode:
RP/0/RP0/CPU0:router # configure RP/0/RP0/CPU0:router(config)# bfd RP/0/RP0/CPU0:router(config-bfd)#bfd address-family ipv4 destination
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.
Syntax Description
Command History
Usage Guidelines
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
Examples
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/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# interface Bundle-Ether 1 RP/0/RP0/CPU0:router(config-if)# bfd address-family ipv4 destination 10.20.20.1bfd address-family ipv4 fast-detect
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.
Command History
Usage Guidelines
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
Examples
The following example enables IPv4 BFD sessions on member links of an Ethernet bundle:
RP/0/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# interface Bundle-Ether 1 RP/0/RP0/CPU0:router(config-if)# bfd address-family ipv4 fast-detectbfd address-family ipv4 minimum-interval
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]
Syntax Description
milliseconds
Shortest interval between sending BFD control packets to a neighbor. The range is 15 to 30000 milliseconds.
Note Command History
Usage Guidelines
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:
- Value of I—Minimum period between sending of BFD control packets.
- Value of I x M
- Value of (I x M) x M—BFD echo packet failure detection time. This is the maximum amount of time that can elapse without receipt of a BFD echo packet before the session is declared down.
When used with bundled VLANs, the following restrictions apply:
- The command specifies control packet intervals only because echo packets are not supported.
- The minimum interval is 250 ms.
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:
- The maximum rate in packets-per-second (pps) for BFD sessions is linecard-dependent. If you have multiple linecards supporting BFD, then the maximum rate for BFD sessions per system is the supported linecard rate multiplied by the number of linecards.
- The maximum number of all BFD sessions on the router is 1024.
- The maximum number of all BFD sessions on the router is 1440.
To calculate the rate for BFD sessions on bundle members running in asynchronous mode without echo:
- Divide 1000 by the value of the minimum interval (as specified by the bfd address-family ipv4 minimum-interval command). This is also the base rate used per member session with 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:
- Determine the echo interval, which is the value of the minimum interval (specified by the bfd address-family ipv4 minimum-interval command) multiplied by the multiplier value (specified by the bfd address-family ipv4 multiplier command). Echo interval = (Min-interval x Multiplier)
- Calculate the overall rate supported for all members on the bundle: Ethernet bundle rate = (1000 / Echo interval) x 64
- Add the asynchronous base rate per bundle member to find the total rate for all bundle links: Total bundle rate = Ethernet bundle rate + (Base asynchronous rate x Number of links)
Task ID
Examples
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/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# interface Bundle-Ether 1 RP/0/RP0/CPU0:router(config-if)# bfd address-family ipv4 minimum-interval 200Related Commands
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.
bfd address-family ipv4 multiplier
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.
Syntax Description
multiplier
Number from 2 to 50.
Note Although the command allows you to configure a minimum of 2, the supported minimum is 3.
Command History
Usage Guidelines
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:
- Value of I—Minimum period between sending of BFD control packets.
- Value of I x M
- 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.
- Value of (I x M) x M—BFD echo packet failure detection time. This is the maximum amount of time that can elapse without receipt of a BFD echo packet before the session is declared down.
Keep the following router-specific rules in mind when configuring the minimum BFD interval:
- The maximum rate in packets-per-second (pps) for BFD sessions is linecard-dependent. If you have multiple linecards supporting BFD, then the maximum rate for BFD sessions per system is the supported linecard rate multiplied by the number of linecards.
- The maximum number of all BFD sessions per linecard is 1024.
- The maximum number of all BFD sessions per linecard is 1440.
To calculate the rate for BFD sessions on bundle members running in asynchronous mode without echo:
- Divide 1000 by the value of the minimum interval (as specified by the bfd address-family ipv4 minimum-interval command). This is also the base rate used per member session with 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:
- Determine the echo interval, which is the value of the minimum interval (specified by the bfd address-family ipv4 minimum-interval command) multiplied by the multiplier value (specified by the bfd address-family ipv4 multiplier command). Echo interval = (Min-interval x Multiplier)
- Calculate the overall rate supported for all members on the bundle: Ethernet bundle rate = (1000 / Echo interval) x 64
- Add the asynchronous base rate per bundle member to find the total rate for all bundle links: Total bundle rate = Ethernet bundle rate + (Base asynchronous rate x Number of links)
Task ID
Examples
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:
- 200 ms control packet interval
- 600 ms control packet failure detection interval
- 600 ms echo packet interval
- 1800 ms echo packet failure detection interval
RP/0/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# interface Bundle-Ether 1 RP/0/RP0/CPU0:router(config-if)# bfd address-family ipv4 minimum-interval 200 RP/0/RP0/CPU0:router(config-if)# bfd address-family ipv4 multiplier 3bfd address-family ipv4 timers
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
Syntax Description
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.
Command History
Usage Guidelines
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
Examples
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/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# interface Bundle-Ether 1 RP/0/RP0/CPU0:router(config-if)# bfd address-family ipv4 timers start 60The 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/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# interface Bundle-Ether 1 RP/0/RP0/CPU0:router(config-if)# bfd address-family ipv4 timers nbr-unconfig 60bfd fast-detect
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.
Syntax Description
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.
Note The disable keyword is available in the following modes only: .
ipv4
Enables Intermediate System-to-Intermediate System (IS-IS) BFD detection of failures in the path between adjacent forwarding engines.
Note The ipv4 keyword is available in IS-IS router configuration mode only.
Command Default
BFD detection of failures in the path between adjacent forwarding engines is disabled.
Command Modes
Neighbor configuration
Session group configuration
Neighbor group configuration
Interface configuration
Interface configuration
Router configuration
Area configuration
Area interface configuration
Interface configuration
Command History
Usage Guidelines
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
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:
- If you enable BFD in area interface configuration mode, it is enabled on the specified interface only.
- If you enable BFD in area configuration mode, it is enabled on all interfaces in the specified area.
- If you enable BFD in router configuration mode, it is enabled on all areas and all associated interfaces in the specified routing process.
The disable keyword is available in the following modes: . 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
Task ID
Operations
bgp
read, write
isis
read, write
mpls-te
read, write
ospf
read, write
multicast
read, write
Examples
The following example shows how to configure BFD on a BGP router:
RP/0/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# router bgp 65000 RP/0/RP0/CPU0:router(config-bgp)# neighbor 192.168.70.24 RP/0/RP0/CPU0:router(config-bgp-nbr)# remote-as 2 RP/0/RP0/CPU0:router(config-bgp-nbr)# bfd fast-detectRelated Commands
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.
bfd minimum-interval
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.
Syntax Description
milliseconds
Interval between sending BFD hello packets to the neighbor. The range is 15 to 30000 milliseconds. For MPLS-TE, the range is 15 to 200 milliseconds.
Command Default
BGP interval: 50 milliseconds
IS-IS interval: 150 milliseconds
OSPF and OSPFv3 interval: 150 milliseconds
MPLS-TE interval: 15 milliseconds
PIM interval: 150 milliseconds
Command Modes
Router configuration
Interface configuration
MPLS TE configuration
Router configuration
Area configuration
Area interface configuration
Router configuration
Area configuration
Interface configuration
Command History
Usage Guidelines
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 and OSPFv3 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 you configure the minimum interval in area interface configuration mode, the updated interval affects the BFD sessions on the specified interface only.
- If you configure the minimum interval in area configuration mode, the updated interval affects the BFD sessions on all interfaces in the specified area.
- If you configure the minimum interval in router configuration mode, the updated interval affects the BFD sessions in all areas and all associated interfaces in the specified routing process.
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:
- The maximum rate in packets-per-second (pps) for BFD sessions is linecard-dependent. If you have multiple linecards supporting BFD, then the maximum rate for BFD sessions per system is the supported linecard rate multiplied by the number of linecards.
- If a session is running in asynchronous mode without echo, then PPS used for this session is (1000 / asynchronous interval in milliseconds).
- If a session is running in asynchronous mode with echo, then PPS used for this session is (1000 / echo interval in milliseconds). This is calculated as: 1000 / value of the bfd minimum-interval command.
Note
The rate for BFD sessions on bundle member links is calculated differently. For more information, see the bfd address-family ipv4 minimum-interval command.
- The maximum number of all BFD sessions per linecard is 1024.
- The maximum number of all BFD sessions per linecard is 1440.
- When asynchronous mode is available, the minimum interval must be greater than or equal to 15 milliseconds for up to 100 sessions on the line card. If you are running the maximum of 1024 sessions, the failure detection interval must be greater than or equal to 150 milliseconds.
- When asynchronous mode is available, the minimum interval must be greater than or equal to 250 milliseconds, with a multiplier of 3 for up to 100 sessions per line card
- When asynchronous mode is available, the minimum interval must be greater than or equal to 15 milliseconds for up to 100 sessions on the line card. If you are running the maximum of 1440 sessions, the failure detection interval must be greater than or equal to 150 milliseconds.
- When echo mode is available, the minimum interval must be greater than or equal to 15 milliseconds for up to 100 sessions on the line card. If you are running the maximum of 1024 sessions, the failure detection interval must be less than or equal to 150 milliseconds.
- When echo mode is available, the minimum interval must be 50 milliseconds with a multiplier of 3.
- When echo mode is available, the minimum interval must be greater than or equal to 15 milliseconds for up to 100 sessions on the line card. If you are running the maximum of 1440 sessions, the failure detection interval must be less than or equal to 150 milliseconds.
Task ID
Task ID
Operations
bgp
read, write
isis
read, write
mpls-te
read, write
ospf
read, write
multicast
read, write
Examples
The following example shows how to set the BFD minimum interval for a BGP routing process:
RP/0/RP0/CPU0:router(config)# router bgp 6500 RP/0/RP0/CPU0:router(config-bgp)# bfd minimum-interval 275The following example shows the configuration of an OSPFv3 routing process named san_jose. The example shows two areas, each of which includes Gigabit Ethernet interfaces. In area 0, the minimum interval is set to 200 at the area level, which means that by virtue of the inheritance rules, the same value is set on all interfaces within the area except those on which a different value is explicitly configured. Given this rule, Gigabit Ethernet interface 1/0/0/0 uses the interval of 200, which is inherited from the area, while interface 2/0/0/0 uses the explicitly configured value of 300.
In area 1, the minimum interval is not configured at the area or interface levels, which means that interfaces 3/0/0/0 and 4/0/0/0 use the default interval of 150.
router ospfv3 san_jose bfd fast-detect area 0 bfd minimum-interval 200 int gige 1/0/0/0 ! int gige 2/0/0/0 bfd minimum-interval 300 ! ! area 1 int gige 3/0/0/0 ! int gige 4/0/0/0 ! !Related Commands
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.
bfd multipath include location
To include specific linecards to host BFD multiple path sessions, use the bfd multipath include location command in the XR Config mode. To remove the configuration, use the no form of this command.
Syntax Description
location node-id Configures BFD multipath on the specified location. The node-id variable is mentioned in the rack/slot/module notation.
Command History
Usage Guidelines
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
Examples
This example shows how to run the bfd multipath include location command on a specific location:
RP/0/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# bfd multipath include location 0/5/CPU0bfd multiplier
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.
Syntax Description
multiplier
Number of times a packet is missed before BFD declares the neighbor down. The ranges are as follows:
Command Modes
Router configuration
Interface configuration
MPLS-TE configuration
Router configuration
Area configuration
Area interface configuration
Interface configuration
Command History
Usage Guidelines
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 you configure a multiplier in area interface configuration mode, the updated multiplier affects the BFD sessions on the specified interface only.
- If you configure a multiplier in area configuration mode, the updated multiplier affects the BFD sessions on all interfaces in the specified area.
- If you configure a multiplier in router configuration mode, the updated multiplier affects the BFD sessions in all areas and all associated interfaces in the specified routing process.
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 .
Task ID
Task ID
Operations
bgp
read, write
isis
read, write
mpls-te
read, write
ospf
read, write
multicast
read, write
Examples
The following example shows how to set the BFD multiplier in a BGP routing process:
RP/0/RP0/CPU0:router(config)# router bgp 65000 RP/0/RP0/CPU0:router(config-bgp)# bfd multiplier 2Related Commands
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.
clear bfd counters
To clear Bidirectional Forwarding Detection (BFD) counters, use the clear bfd counters command in XR EXEC mode.
clear bfd counters { ipv4 | [ singlehop | multihop ] | ipv6 | [ singlehop | multihop ] | all | label } [packet] [timing] [ interface type interface-path-id ] location node-id
Syntax Description
ipv4
(Optional) Clears BFD over IPv4 information only.
ipv6
(Optional) Clears BFD over IPv6 information only.
singlehop
(Optional) Clears BFD singlehop information only.
multihop
(Optional) Clears BFD multihop information only.
all
(Optional) Clears both BFD over IPv4 and BFD over IPv6 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.
Note Use the show interfaces command to see a list of all interfaces currently configured on the router.
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.
Command Default
The default is the default address family identifier (AFI) that is set by the set default-afi command, IPv4 or IPv6.
Command History
Usage Guidelines
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 specifying a physical interface, the naming notation is rack/slot/module/port. The slash between values is required as part of the notation. An explanation of each component of the naming notation is as follows:
- If specifying a virtual interface, the number range varies, depending on interface type.
Both IPv4 and IPv6 BFD sessions can run simultaneously on the same line card.
Examples
The following example shows how to clear the BFD IPv6 packet counters on a POS interface:
RP/0/RP0/CPU0:router# clear bfd counters packet ipv6 interface POS 0/1/0/0 location 0/1/cpu0The following example shows how to clear the BFD IPv4 timing counters:
RP/0/RP0/CPU0:router# clear bfd counters ipv4 timing location 0/5/cpu0dampening (BFD)
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
Syntax Description
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.
Note The maximum delay must be greater than the initial delay.
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.
Command History
Usage Guidelines
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:
- If a session is brought down, then dampening is applied before a session is allowed to transition to initial/up states.
- Length of time a session is dampened grows exponentially with continuous session flap.
- If a session remains up for minimum two minutes, then the length of time a session dampens with the next session flap is reset to the initial dampening value.
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
Examples
The following example shows how to configure an initial and maximum delay for BFD session startup on BFD bundle members:
RP/0/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# bfd RP/0/RP0/CPU0:router(config-bfd)# dampening bundle-member initial-wait 8000 RP/0/RP0/CPU0:router(config-bfd)# dampening bundle-member maximum-wait 15000The following example shows how to change the default initial-wait for BFD on a non-bundle interface:
RP/0/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# bfd RP/0/RP0/CPU0:router(config-bfd)# dampening initial-wait 30000 RP/0/RP0/CPU0:router(config-bfd)# dampening maximum-wait 35000echo disable
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.
Command History
Usage Guidelines
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
Examples
The following example shows how to disable echo mode on a router:
RP/0/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# bfd RP/0/RP0/CPU0:router(config-bfd)# echo disableThe following example shows how to disable echo mode on an individual interface:
RP/0/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# bfd RP/0/RP0/CPU0:router(config-bfd)# interface gigabitethernet 0/1/0/0 RP/0/RP0/CPU0:router(config-bfd-if)# echo disableecho ipv4 source
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.
Syntax Description
Command Default
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.
Command History
Usage Guidelines
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
Examples
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/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# bfd RP/0/RP0/CPU0:router(config-bfd)# echo ipv4 source 10.10.10.1The 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/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# bfd RP/0/RP0/CPU0:router(config-bfd)# interface gigabitethernet 0/1/0/0 RP/0/RP0/CPU0:router(config-bfd-if)# echo ipv4 source 10.10.10.1The 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/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# bfd RP/0/RP0/CPU0:router(config-bfd)# interface pos 0/1/0/0 RP/0/RP0/CPU0:router(config-bfd-if)# echo ipv4 source 10.10.10.1echo latency detect
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 ] ]
Syntax Description
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.
Command History
Usage Guidelines
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
Examples
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/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# bfd RP/0/RP0/CPU0:router(config-bfd)# echo latency detectThe 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/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# bfd RP/0/RP0/CPU0:router(config-bfd)# echo latency detect percentage 200The 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/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# bfd RP/0/RP0/CPU0:router(config-bfd)# echo latency detect percentage 100 count 3echo startup validate
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.
Syntax Description
Command History
Usage Guidelines
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
Examples
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/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# bfd RP/0/RP0/CPU0:router(config-bfd)# echo startup validateThe 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/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# bfd RP/0/RP0/CPU0:router(config-bfd)# echo startup validate forceinterface (BFD)
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.
Syntax Description
type
Interface type. For more information, use the question mark (?) online help function.
interface-path-id
Physical interface or virtual interface.
Note Use the show interfaces command to see a list of all interfaces currently configured on the router.
For more information about the syntax for the router, use the question mark (?) online help function.
Command History
Usage Guidelines
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 specifying a physical interface, the naming notation is rack/slot/module/port. The slash between values is required as part of the notation. An explanation of each component of the naming notation is as follows:
- If specifying a virtual interface, the number range varies, depending on interface type.
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. To enable or disable loose IPv6 uRPF checking on an IPv6 interface, use the [no] ipv6 verify unicast source reachable-via any command in interface configuration mode.
Task ID
Examples
The following example shows how to enter BFD interface configuration mode for a Gigabit Ethernet interface:
RP/0/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# bfd RP/0/RP0/CPU0:router(config-bfd)# interface gigabitethernet 0/1/0/0 RP/0/RP0/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/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# bfd RP/0/RP0/CPU0:router(config-bfd)# interface pos 0/1/0/0 RP/0/RP0/CPU0:router(config-bfd-if)#Related Commands
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.
ipv6 verify unicast source reachable-via any
Enables and disables loose IPv6 uRPF checking on an IPv6 interface.
Displays BFD information.
ipv6 checksum
To enable and disable IPv6 checksum calculations on BFD UDP packets globally or on a BFD interface, use the ipv6 checksum command in Bidirectional Forwarding Detection (BFD) or BFD interface configuration mode. To return to the default, use the no form of this command.
BFD Configuration
ipv6 checksum disable
no ipv6 checksum disable
BFD Interface Configuration
ipv6 checksum [disable]
no ipv6 checksum [disable]
Syntax Description
Command History
Usage Guidelines
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.
IPv6 checksum calculations for UDP packets are disable by default for BFD sessions. You can enable IPv6 checksum support either globally for all BFD sessions, or on an individual interface.
Task ID
Examples
The following example shows how to enable IPv6 checksum calculations for UDP packets for all BFD sessions on the router:
RP/0/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# bfd RP/0/RP0/CPU0:router(config-bfd)# no ipv6 checksum disableThe following example shows how to disable IPv6 checksum calculations for UDP packets for all BFD sessions on the router:
RP/0/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# bfd RP/0/RP0/CPU0:router(config-bfd)# ipv6 checksum disableThe following example shows how to enable echo mode for BFD sessions on an individual interface:
RP/0/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# bfd RP/0/RP0/CPU0:router(config-bfd)# interface gigabitethernet 0/1/0/0 RP/0/RP0/CPU0:router(config-bfd-if)# ipv6 checksumThe following example shows how to disable echo mode for BFD sessions on an individual interface:
RP/0/RP0/CPU0:router# configure RP/0/RP0/CPU0:router(config)# bfd RP/0/RP0/CPU0:router(config-bfd)# interface gigabitethernet 0/1/0/0 RP/0/RP0/CPU0:router(config-bfd-if)# ipv6 checksum disablemultihop ttl-drop-threshold
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.
Syntax Description
Command History
Usage Guidelines
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
This configuration command is only applicable for BFD multihop sessions.
Task ID
Examples
This example shows how to set the maximum ttl value as 2 using themultihop-ttl-drop-threshold command:
RP/0/RP0/CPU0:routerconfigure RP/0/RP0/CPU0:routerbfd multihop ttl-drop threshold 2show bfd
To display Bidirectional Forwarding Detection (BFD) information for a specific location, use the show bfd command in XR EXEC mode.
show bfd [ ipv4 | [ singlehop | multihop ] | ipv6 [ singlehop | ] | all |label ] interface [ destination | ] [ location node-id ]
Syntax Description
ipv4
(Optional) Displays BFD over IPv4 information only.
multihop
(Optional) Displays BFD multihop information only.
singlehop
(Optional) Displays BFD singlehop information only.
ipv6
(Optional) Displays BFD over IPv6 information only.
all
(Optional) Displays both BFD over IPv4 and BFD over IPv6 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.
Command Default
The default is the default address family identifier (AFI) that is set by the set default-afi command, IPv4 or IPv6.
Command History
Usage Guidelines
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
Examples
The following example shows the output from the show bfd command:
RP/0/RP0/CPU0:router# show bfd IPV4 Sessions Up: 0, Down: 0, Total: 0The following example shows the output from the show bfd all command:
RP/0/RP0/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: 11The following example shows the output from the show bfd ipv4 command:
RP/0/RP0/CPU0:router# show bfd ipv4 IPV4 Sessions Up: 0, Down: 0, Total: 0The following example shows the output from the show bfd ipv6 command:
RP/0/RP0/CPU0:router# show bfd ipv6 IPV6 Sessions Up: 0, Down: 0, Total: 0The following example shows the output from the show bfd ipv4 location command:
RP/0/RP0/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 : 0x0show bfd client
To display Bidirectional Forwarding Detection (BFD) client information, use the show bfd client command in XR EXEC mode.
Syntax Description
detail
(Optional) Specifies detailed client information including number of sessions and client reconnects.
Command Default
Enter the show bfd client command without specifying the detail keyword to display summarized BFD client information.
Command History
Usage Guidelines
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
Examples
The following example shows the output from the show bfd client command:
RP/0/RP0/CPU0:router# show bfd client Name Node Num sessions --------------- ---------- -------------- bgp 0//CPU0 0 isis 0//CPU0 0 isis 0//CPU0 0show bfd counters
To display Bidirectional Forwarding Detection (BFD) counter information, use the show bfd counters command in XR EXEC mode.
show bfd counters [ ipv4 | [ singlehop | multihop ] | ipv6 [ singlehop | ] | all | label ] packet [ interface type interface-path-id ] location node-id
Syntax Description
ipv4
(Optional) Displays BFD over IPv4 information only.
ipv6
(Optional) Displays BFD over IPv6 information only.
singlehop
(Optional) Displays BFD singlehop information only.
multihop
(Optional) Displays BFD multihop information only.
all
(Optional) Displays both BFD over IPv4 and BFD over IPv6 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.
Note Use the show interfaces command to see a list of all interfaces currently configured on the router.
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.
Command Default
The default is the default address family identifier (AFI) that is set by the set default-afi command, IPv4 or IPv6.
Command History
Usage Guidelines
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 specifying a physical interface, the naming notation is rack/slot/module/port. The slash between values is required as part of the notation. An explanation of each component of the naming notation is as follows:
- If specifying a virtual interface, the number range varies, depending on interface type.
Task ID
Examples
The following example shows the output from the show bfd counters packet command for both IPv4 and IPv6:
RP/0/RP0/CPU0:router# show bfd counters packet all interface POS 0/1/0/0 location 0/1/cpu0 Mon Nov 5 08:49:51.950 UTC IPv4: ----- POS 0/1/0/0 Recv Xmit Recv Xmit Async: 520 515 Echo: 9400 9400 IPv6: ----- POS 0/1/0/0 Recv Xmit Recv Xmit Async: 237 237 Echo: 0 0The following example shows the output from the show bfd counters packet command for IPv4:
RP/0/RP0/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 570337show bfd mib session
To display IPv4 and IPv6 Bidirectional Forwarding Detection (BFD) MIB session information, use the show bfd mib session command in XR EXEC mode.
Syntax Description
location node-id
(Optional) Displays all IPv4 and IPv6 BFD MIB session information stored on the specified node. The node-id argument is entered in the rack/slot/module notation.
Command Default
When node-id is not specified, information for all IPv4 and IPv6 BFD MIB sessions, stored on the route processor node, is displayed.
Command History
Usage Guidelines
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 and IPv6 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 and IPv6 BFD MIB sessions, stored on the specified node (linecard), is displayed, and this information is updated automatically without SNMP operations being performed.
Task ID
Examples
The following example displays all IPv4 and IPv6 BFD MIB session information stored on the RP node:
RP/0/RP0/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 cachedThe following example displays all IPv4 and IPv6 BFD MIB session information stored on 0/1/CPU0:
RP/0/RP0/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
Table 3 show bfd mib Field Descriptions 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.
show bfd multipath
To display information concerning only BFD multipath sessions, use the show bfd multipath command in the XR EXEC mode.
Syntax Description
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.
Command History
Usage Guidelines
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
Examples
This example shows the sample output for show bfd multipath command:
RP/0/RP0/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 UPshow bfd session
To display Bidirectional Forwarding Detection (BFD) session information, use the show bfd session command in XR EXEC mode.
show bfd [ ipv4 | [ singlehop | multihop ] | ipv6 | [ singlehop | multihop ] | all | label ] session [ interface type interface-path-id [ destination ip-address ] [detail] [in-label] ] location node-id
Syntax Description
ipv4
(Optional) Displays BFD over IPv4 information only.
ipv6
(Optional) Displays BFD over IPv6 information only.
singlehop
(Optional) Displays BFD singlehop information only.
multihop
(Optional) Displays BFD multihop information only.
all
(Optional) Displays both BFD over IPv4 and BFD over IPv6 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.
Note Use the show interfaces command to see a list of all interfaces currently configured on the router.
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.
Command Default
The default is the default address family identifier (AFI) that is set by the set default-afi command, IPv4 or IPv6.
Command History
Usage Guidelines
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 specifying a physical interface, the naming notation is rack/slot/module/port. The slash between values is required as part of the notation. An explanation of each component of the naming notation is as follows:
- If specifying a virtual interface, the number range varies, depending on interface type.
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
Examples
The following example shows the output from the show bfd session command with the detail keyword and IPv4 as the default:
RP/0/RP0/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 3The following example shows the output from the show bfd session command with the all keyword, which displays both IPv4 and IPv6 information:
RP/0/RP0/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) UPshow bfd summary
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 XR EXEC mode.
Syntax Description
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.
Command History
Usage Guidelines
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
Examples
This example shows the sample output from the show bfd summary command for a specified location:
RP/0/RP0/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 4000This example shows the sample output from the show bfd summary command:
RP/0/RP0/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
