The documentation set for this product strives to use bias-free language. For the purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product. Learn more about how Cisco is using Inclusive Language.
The BFD-EIGRP Support feature configures the Enhanced Interior Gateway Routing Protocol (EIGRP) with Bidirectional Forwarding
Detection (BFD) so that EIGRP registers with BFD and receives all forwarding path detection failure messages from BFD.
Prerequisites for
BFD-EIGRP Support
Enhanced
Interior Gateway Routing Protocol (EIGRP) must be running on all participating
routers.
The baseline
parameters for Bidirectional Forwarding Detection (BFD) sessions on the
interfaces over which you want to run BFD sessions to BFD neighbors must be
configured using the
bfd command.
Information About BFD - EIGRP Support
Overview of
BFD-EIGRP Support
The BFD-EIGRP
Support feature configures Bidirectional Forwarding Detection (BFD) feature for
Enhanced Interior Gateway Routing Protocol (EIGRP) so that EIGRP registers with
the BFD sessions on the routing interfaces, and receives forwarding path
detection failure messages from BFD.
Use
bfd intervalmillisecondsmin_rxmillisecondsmultiplierinterval-multiplier command to enable BFD on any
interface. Use the
bfd
all-interfaces command in router configuration mode to enable BFD
for all of the interfaces where EIGRP routing is enabled. Use the
bfd interfacetype
number command in router configuration mode to enable BFD for a
subset of the interfaces where EIGRP routing is enabled.
(Optional)
Displays the interfaces for which BFD support for EIGRP has been enabled.
Configuration Examples for BFD - EIGRP Support
Example: Configuring BFD in an EIGRP Network with Echo Mode Enabled by Default
In the following example, the EIGRP network contains DeviceA, DeviceB, and DeviceC. Fast Ethernet interface 1/0 on DeviceA
is connected to the same network as Fast Ethernet interface 1/0 on Device B. Fast Ethernet interface 1/0 on DeviceB is connected
to the same network as Fast Ethernet interface 1/0 on DeviceC.
DeviceA and DeviceB are running BFD Version 1, which supports echo mode, and DeviceC is running BFD Version 0, which does
not support echo mode. The BFD sessions between DeviceC and its BFD neighbors are said to be running echo mode with asymmetry
because echo mode will run on the forwarding path for DeviceA and DeviceB, and their echo packets will return along the same
path for BFD sessions and failure detections, while their BFD neighbor DeviceC runs BFD Version 0 and uses BFD controls packets
for BFD sessions and failure detections.
The figure below shows a large EIGRP network with several devices, three of which are BFD neighbors that are running EIGRP
as their routing protocol.
The example, starting in global configuration mode, shows the configuration of BFD.
Configuration for DeviceA
interface Fast Ethernet0/0
no shutdown
ip address 10.4.9.14 255.255.255.0
duplex auto
speed auto
!
interface Fast Ethernet1/0
ip address 172.16.1.1 255.255.255.0
bfd interval 50 min_rx 50 multiplier 3
no shutdown
duplex auto
speed auto
!
router eigrp 11
network 172.16.0.0
bfd all-interfaces
auto-summary
!
ip default-gateway 10.4.9.1
ip default-network 0.0.0.0
ip route 0.0.0.0 0.0.0.0 10.4.9.1
ip route 172.16.1.129 255.255.255.255 10.4.9.1
!
no ip http server
!
logging alarm informational
!
control-plane
!
line con 0
exec-timeout 30 0
stopbits 1
line aux 0
stopbits 1
line vty 0 4
login
!
!
end
Configuration for DeviceB
!
interface Fast Ethernet0/0
no shutdown
ip address 10.4.9.34 255.255.255.0
duplex auto
speed auto
!
interface Fast Ethernet1/0
ip address 172.16.1.2 255.255.255.0
bfd interval 50 min_rx 50 multiplier 3
no shtdown
duplex auto
speed auto
!
router eigrp 11
network 172.16.0.0
bfd all-interfaces
auto-summary
!
ip default-gateway 10.4.9.1
ip default-network 0.0.0.0
ip route 0.0.0.0 0.0.0.0 10.4.9.1
ip route 172.16.1.129 255.255.255.255 10.4.9.1
!
no ip http server
!
logging alarm informational
!
control-plane
!
line con 0
exec-timeout 30 0
stopbits 1
line aux 0
stopbits 1
line vty 0 4
login
!
!
end
Configuration for DeviceC
!
!
interface Fast Ethernet0/0
no shutdown
ip address 10.4.9.34 255.255.255.0
duplex auto
speed auto
!
interface Fast Ethernet1/0
ip address 172.16.1.2 255.255.255.0
bfd interval 50 min_rx 50 multiplier 3
no shutdown
duplex auto
speed auto
!
router eigrp 11
network 172.16.0.0
bfd all-interfaces
auto-summary
!
ip default-gateway 10.4.9.1
ip default-network 0.0.0.0
ip route 0.0.0.0 0.0.0.0 10.4.9.1
ip route 172.16.1.129 255.255.255.255 10.4.9.1
!
no ip http server
!
logging alarm informational
!
control-plane
!
line con 0
exec-timeout 30 0
stopbits 1
line aux 0
stopbits 1
line vty 0 4
login
!
!
end
The output from the
showbfdneighborsdetails command from DeviceA verifies that BFD sessions are created among all three devices and that EIGRP is registered for BFD
support. The first group of output shows that DeviceC with the IP address 172.16.1.3 runs BFD Version 0 and therefore does
not use the echo mode. The second group of output shows that DeviceB with the IP address 172.16.1.2 runs BFD Version 1, and
the 50 millisecond BFD interval parameter had been adopted. The relevant command output is shown in bold in the output.
DeviceA# show bfd neighbors detailsOurAddrNeighAddr
LD/RD RH/RS Holdown(mult) State Int
172.16.1.1 172.16.1.3
5/3 1(RH) 150 (3 ) Up Fa1/0
Session state is UP and not using echo function.
Local Diag: 0, Demand mode: 0, Poll bit: 0
MinTxInt: 50000, MinRxInt: 50000, Multiplier: 3
Received MinRxInt: 50000, Received Multiplier: 3
Holdown (hits): 150(0), Hello (hits): 50(1364284)
Rx Count: 1351813, Rx Interval (ms) min/max/avg: 28/64/49 last: 4 ms ago
Tx Count: 1364289, Tx Interval (ms) min/max/avg: 40/68/49 last: 32 ms ago
Registered protocols: EIGRP
Uptime: 18:42:45
Last packet: Version: 0
- Diagnostic: 0
I Hear You bit: 1 - Demand bit: 0
Poll bit: 0 - Final bit: 0
Multiplier: 3 - Length: 24
My Discr.: 3 - Your Discr.: 5
Min tx interval: 50000 - Min rx interval: 50000
Min Echo interval: 0
OurAddr NeighAddr
LD/RD RH/RS Holdown(mult) State Int
172.16.1.1 172.16.1.2
6/1 Up 0 (3 ) Up Fa1/0
Session state is UP and using echo function with 50 ms interval.
Local Diag: 0, Demand mode: 0, Poll bit: 0
MinTxInt: 1000000, MinRxInt: 1000000, Multiplier: 3
Received MinRxInt: 1000000, Received Multiplier: 3
Holdown (hits): 3000(0), Hello (hits): 1000(317)
Rx Count: 305, Rx Interval (ms) min/max/avg: 1/1016/887 last: 448 ms ago
Tx Count: 319, Tx Interval (ms) min/max/avg: 1/1008/880 last: 532 ms ago
Registered protocols: EIGRP
Uptime: 00:04:30
Last packet: Version: 1
- Diagnostic: 0
State bit: Up - Demand bit: 0
Poll bit: 0 - Final bit: 0
Multiplier: 3 - Length: 24
My Discr.: 1 - Your Discr.: 6
Min tx interval: 1000000 - Min rx interval: 1000000
Min Echo interval: 50000
The output from the
showbfdneighborsdetails command on Device B verifies that BFD sessions have been created and that EIGRP is registered for BFD support. As previously
noted, DeviceA runs BFD Version 1, therefore echo mode is running, and DeviceC runs BFD Version 0, so echo mode does not run.
The relevant command output is shown in bold in the output.
DeviceB# show bfd neighbors details OurAddr NeighAddr
LD/RD RH/RS Holdown(mult) State Int
172.16.1.2 172.16.1.1
1/6 Up 0 (3 ) Up Fa1/0
Session state is UP and using echo function with 50 ms interval.
Local Diag: 0, Demand mode: 0, Poll bit: 0
MinTxInt: 1000000, MinRxInt: 1000000, Multiplier: 3
Received MinRxInt: 1000000, Received Multiplier: 3
Holdown (hits): 3000(0), Hello (hits): 1000(337)
Rx Count: 341, Rx Interval (ms) min/max/avg: 1/1008/882 last: 364 ms ago
Tx Count: 339, Tx Interval (ms) min/max/avg: 1/1016/886 last: 632 ms ago
Registered protocols: EIGRP
Uptime: 00:05:00
Last packet: Version: 1
- Diagnostic: 0
State bit: Up - Demand bit: 0
Poll bit: 0 - Final bit: 0
Multiplier: 3 - Length: 24
My Discr.: 6 - Your Discr.: 1
Min tx interval: 1000000 - Min rx interval: 1000000
Min Echo interval: 50000
OurAddr NeighAddr
LD/RD RH/RS Holdown(mult) State Int
172.16.1.2 172.16.1.3
3/6 1(RH) 118 (3 ) Up Fa1/0
Session state is UP and not using echo function.
Local Diag: 0, Demand mode: 0, Poll bit: 0
MinTxInt: 50000, MinRxInt: 50000, Multiplier: 3
Received MinRxInt: 50000, Received Multiplier: 3
Holdown (hits): 150(0), Hello (hits): 50(5735)
Rx Count: 5731, Rx Interval (ms) min/max/avg: 32/72/49 last: 32 ms ago
Tx Count: 5740, Tx Interval (ms) min/max/avg: 40/64/50 last: 44 ms ago
Registered protocols: EIGRP
Uptime: 00:04:45
Last packet: Version: 0
- Diagnostic: 0
I Hear You bit: 1 - Demand bit: 0
Poll bit: 0 - Final bit: 0
Multiplier: 3 - Length: 24
My Discr.: 6 - Your Discr.: 3
Min tx interval: 50000 - Min rx interval: 50000
Min Echo interval: 0
The figure below shows that Fast Ethernet interface 1/0 on DeviceB has failed. When Fast Ethernet interface 1/0 on DeviceB
is shut down, the BFD statistics of the corresponding BFD sessions on DeviceA and DeviceB are reduced.
When Fast Ethernet interface 1/0 on DeviceB fails, BFD will no longer detect Device B as a BFD neighbor for DeviceA or for
DeviceC. In this example, Fast Ethernet interface 1/0 has been administratively shut down on DeviceB.
The following output from the
showbfdneighbors command on DeviceA now shows only one BFD neighbor for DeviceA in the EIGRP network. The relevant command output is shown
in bold in the output.
DeviceA# show bfd neighborsOurAddr NeighAddr
LD/RD RH/RS Holdown(mult) State Int
172.16.1.1 172.16.1.3
5/3 1(RH) 134 (3 ) Up Fa1/0
The following output from the
showbfdneighbors command on DeviceC also now shows only one BFD neighbor for DeviceC in the EIGRP network. The relevant command output is
shown in bold in the output.
DeviceC# show bfd neighborsOurAddr NeighAddr
LD/RD RH Holdown(mult) State Int
172.16.1.3 172.16.1.1
3/5 1 114 (3 ) Up Fa1/0
The Cisco Support website provides extensive online resources,
including documentation and tools for troubleshooting and
resolving technical issues with Cisco products and technologies.
To receive security and technical information about your
products, you can subscribe to various services, such as the
Product Alert Tool (accessed from Field Notices), the Cisco
Technical Services Newsletter, and Really Simple Syndication
(RSS) Feeds.
Access to most tools on the Cisco Support website requires a
Cisco.com user ID and password.
The following table provides release information about the feature or features described in this module. This table lists
only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise,
subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco
Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Table 1. Feature Information for BFD-EIGRP Support
Feature Name
Releases
Feature Information
BFD-EIGRP Support
Cisco IOS XE Everest 16.6.2
The BFD-EIGRP Support feature configures the Enhanced Interior Gateway Routing Protocol (EIGRP) with Bidirectional Forwarding
Detection (BFD) so that EIGRP registers with BFD and receives all forwarding path detection failure messages from BFD.
In Cisco IOS XE Everest 16.6.2, this feature was implemented on Cisco Catalyst 9400 Series Switches.