BFD Protocol Configurations
This chapter describes the BFD protocol configurations.
OSPF—BFD Single-Hop Session
This section provides the steps for configuring BFD for Single-Hop OSPF.
Topology
Single-Hop OSPF Topology
R1
 
| R1#configure terminal | Enter the Configure mode. | 
| R1(config)#interface lo  | Enter the Interface configuration mode for lo | 
| R1(config-if)#ip address 1.1.1.1/32 secondary | Assign IP Address | 
| R1(config)#interface eth1 | Enter the Interface configuration mode for eth1. | 
| R1(config-if)#ip address 10.1.1.1/24 | Assign IP Address | 
| R1(config-if)#exit | Exit the Interface configuration mode. | 
| R1(config)#router ospf 100 | Enter the Router mode for OSPF. | 
| R1(config-router)#network 10.1.1.0/24 area 1 | Advertise network 10.1.1.0/24 in OSPF area 1. | 
| R1(config-router)#network 1.1.1.1/32 area 1 | Advertise loopback network 1.1.1.1/32 in OSPF area 1. | 
| R1(config-router)#bfd all-interfaces | Enable BFD for all neighbors. | 
| R1(config-router)#commit | Commit the configuration on the node | 
| R1(config-router)#exit | Exit the router mode | 
R2
 
| R2#configure terminal | Enter the Configure mode. | 
| R2(config)#interface eth1 | Enter the Interface configuration mode for eth1. | 
| R2(config-if)#ip address 10.1.1.2/24 | Assign IP Address | 
| R2(config-if)#exit | Exit the Interface configuration mode. | 
| R2(config)#interface eth2 | Enter the Interface configuration mode for eth2. | 
| R2(config-if)#ip address 20.1.1.1/24 | Assign IP Address | 
| R2(config-if)#exit | Exit the Interface configuration mode | 
| R2(config)#router ospf 100 | Enter the Router mode for OSPF. | 
| R2(config-router)#network 10.1.1.0/24 area 1 | Advertise network 10.1.1.0/24 in OSPF area 1. | 
| R2(config-router)#network 20.1.1.0/24 area 1 | Advertise network 20.1.1.0/24 in OSPF area 1. | 
| R2(config-router)#network 2.2.2.2/32 area 1 | Advertise loopback network 2.2.2.2/32 in OSPF area 1.  | 
| R2(config-router)#bfd all-interfaces | Enable BFD for all neighbors. | 
| R2(config)#interface lo | Enter the Interface configuration mode for lo | 
| R2(config-if)#ip address 2.2.2.2/32 secondary | Assign IP Address | 
| R2(config-router)#commit | Commit the configuration on the node | 
| R2(config-router)#exit | Exit the router mode. | 
R3
 
| R3#configure terminal | Enter the Configure mode. | 
| R3(config)#interface lo | Enter the Interface configuration mode for lo | 
| R3(config-if)#ip address 3.3.3.3/32 secondary | Assign IP Address | 
| R3(config)#interface eth2 | Enter the Interface configuration mode for eth2. | 
| R3(config-if)#ip address 20.1.1.2/24 | Assign IP Address. | 
| R3(config-if)#exit | Exit the Interface configuration mode. | 
| R3(config)#router ospf 100 | Enter the Router mode for OSPF. | 
| R3(config-router)#network 20.1.1.0/24 area 1 | Advertise network 20.1.1.0/24 in OSPF area 1. | 
| R3(config-router)#network 3.3.3.3/32 area 1 | Advertise loopback network 3.3.3.3/32 in OSPF area 1. | 
| R3(config-router)#bfd all-interfaces | Enable BFD for all neighbors | 
| R3(config-router)#commit | Commit the configuration on the node | 
| R3(config-router)#exit | Exit the router mode. | 
Validation
R1
R1#show ip ospf n
 
Total number of full neighbors: 1
OSPF process 100 VRF(default):
Neighbor ID     Pri   State            Dead Time   Address         Interface   Instance ID
2.2.2.2             1   Full/Backup      00:00:35    10.1.1.2            xe23          0
 
 
R1#show bfd session
 
BFD process for VRF: (DEFAULT VRF)
================================================================================
Sess-Idx   Remote-Disc  Lower-Layer  Sess-Type   Sess-State  UP-Time   Interface  Down-Reason  Remote-Addr
1                        1                 IPv4         Single-Hop      Up          00:02:55       xe23       NA                   10.1.1.2/32
257                    0                 IPv4         Multi-Hop       Up           00:00:18      xe8         NA                    3.3.3.3/32
Number of Sessions:    2
 
R1#show bfd session detail
 
BFD process for VRF: (DEFAULT VRF)
================================================================================
====
 
Session Interface Index : 10023          Interface name :xe23
Session Index : 1
Lower Layer : IPv4                                 Version : 1
Session Type : Single Hop                     Session State : Up
Local Discriminator : 1                          Local Address : 10.1.1.1/32
Remote Discriminator : 1                      Remote Address : 10.1.1.2/32
Local Port : 49152                                 Remote Port : 3784
Options :
 
Diagnostics : None
 
Timers in Milliseconds :
Min Tx: 250                    Min Rx: 250                    Multiplier: 3
Neg Tx: 250                    Neg Rx: 250                    Neg detect mult: 3
Min echo Tx: 1000          Min echo Rx: 1000         Neg echo intrvl: 0
Storage type : 2
Sess down time : 00:00:00
Sess Down Reason : NA
Bfd GTSM Disabled
Bfd Authentication Disabled
 
Counters values:
Pkt In : 00000000000000000814                  Pkt Out : 00000000000000000814
Pkts Drop : 00000000000000000000           Auth Pkts Drop : 00000000000000000000
Echo Out : 00000000000000000000            IPv6 Echo Out : 00000000000000000000
IPv6 Pkt In : 00000000000000000000           IPv6 Pkt Out : 00000000000000000000
UP Count : 1                                                    UPTIME : 00:02:59
 
Protocol Client Info:
BGP-> Client ID: 44      Flags: 4
----------------------------------------------------------
 
Session Interface Index : 0                    Session Index : 257
Lower Layer : IPv4                                 Version : 1
Session Type : Multihop Arbit Path       Session State : Up
Local Discriminator : 257                      Local Address : 1.1.1.1/32
Remote Discriminator : 0                      Remote Address : 3.3.3.3/32
Local Port : 49153                                  Remote Port : 4784
Options :
 
Diagnostics : None
 
Timers in Milliseconds :
Min Tx: 250                   Min Rx: 250                   Multiplier: 3
Neg Tx: 0                       Neg Rx: 0                       Neg detect mult: 0
Min echo Tx: 1000         Min echo Rx: 1000         Neg echo intrvl: 0
Storage type : 2
Sess down time : 00:00:00
Sess Down Reason : NA
Bfd GTSM Disabled
Bfd Authentication Disabled
 
Counters values:
Pkt In : 00000000000000000000                 Pkt Out : 00000000000000000107
Pkts Drop : 00000000000000000000           Auth Pkts Drop : 00000000000000000000
Echo Out : 00000000000000000000            IPv6 Echo Out : 00000000000000000000
IPv6 Pkt In : 00000000000000000000          IPv6 Pkt Out : 00000000000000000000
UP Count : 0                                                  UPTIME : 00:00:00
R3#show bfd session
BFD process for VRF: (DEFAULT VRF)
=====================================================================================
Sess-Idx Remote-Disc Lower-Layer Sess-Type Sess-State UP-Time Interface     Down-Reason  Remote-Addr
1            1       IPv4        Single-Hop   Up      00:04:33   eth2             NA           20.1.1.3/32
---------------------------------------------------------------------------------------
 
R1#show bfd session detail
======================================================
 
Session Interface Index : 3              
Interface name : eth1                    Session Index : 1
Lower Layer : IPv4                       Version : 1
Session Type : Single Hop                Session State : Up
Local Discriminator : 1                  Local Address : 10.1.1.1/32
Remote Discriminator : 1                 Remote Address : 10.1.1.2/32
Local Port : 49152                       Remote Port : 3784
Options :
 
Diagnostics : None
 
Timers in Milliseconds :
Min Tx: 250               Min Rx: 250               Multiplier: 3
Neg Tx: 250               Neg Rx: 250               Neg detect mult: 3
Min echo Tx: 1000         Min echo Rx: 1000         Neg echo intrvl: 0
Storage type : 2
Sess down time : 00:00:00
Bfd GTSM Disabled
Bfd Authentication Disabled
 
Counters values:
Pkt In : 0000000000000cf3                Pkt Out : 0000000000000cfc
Echo Out : 0000000000000000              IPv6 Echo Out : 0000000000000000
IPv6 Pkt In : 0000000000000000           IPv6 Pkt Out : 0000000000000000
UP Count : 1                             UPTIME : 00:12:12
 
Protocol Client Info:
OSPF-> Client ID: 4      Flags: 4
----------------------------------------------------------
Number of Sessions:    1
 
R2#show bfd session detail
======================================================
 
Session Interface Index : 3              
Interface name : eth1                    Session Index : 1
Lower Layer : IPv4                       Version : 1
Session Type : Single Hop                Session State : Up
Local Discriminator : 1                  Local Address : 10.1.1.2/32
Remote Discriminator : 1                 Remote Address : 10.1.1.1/32
Local Port : 49152                       Remote Port : 3784
Options :
 
Diagnostics : None
 
Timers in Milliseconds :
Min Tx: 250               Min Rx: 250               Multiplier: 3
Neg Tx: 250               Neg Rx: 2000              Neg detect mult: 3
Min echo Tx: 1000         Min echo Rx: 1000         Neg echo intrvl: 0
Storage type : 2
Sess down time : 00:00:00
Bfd GTSM Disabled
Bfd Authentication Disabled
 
Counters values:
Pkt In : 0000000000000d6f                Pkt Out : 0000000000000da5
Echo Out : 0000000000000000              IPv6 Echo Out : 0000000000000000
IPv6 Pkt In : 0000000000000000           IPv6 Pkt Out : 0000000000000000
UP Count : 1                             UPTIME : 00:12:39
 
Protocol Client Info:
OSPF-> Client ID: 4      Flags: 4
----------------------------------------------------------
 
Session Interface Index : 4              
Interface name : eth1                    Session Index : 2
Lower Layer : IPv4                       Version : 1
Session Type : Single Hop                Session State : Up
Local Discriminator : 2                  Local Address : 20.1.1.1/32
Remote Discriminator : 1                 Remote Address : 20.1.1.2/32
Local Port : 49153                       Remote Port : 3784
Options :
 
Diagnostics : None
 
Timers in Milliseconds :
Min Tx: 250               Min Rx: 250               Multiplier: 3
Neg Tx: 250               Neg Rx: 2000              Neg detect mult: 3
Min echo Tx: 1000         Min echo Rx: 1000         Neg echo intrvl: 0
Storage type : 2
Sess down time : 00:00:00
Bfd GTSM Disabled
Bfd Authentication Disabled
 
Counters values:
Pkt In : 0000000000000d30                Pkt Out : 0000000000000d5e
Echo Out : 0000000000000000              IPv6 Echo Out : 0000000000000000
IPv6 Pkt In : 0000000000000000           IPv6 Pkt Out : 0000000000000000
UP Count : 1                             UPTIME : 00:12:24
 
R2
R2#show ip ospf neighbor
 
Total number of full neighbors: 2
OSPF process 100 VRF(default):
Neighbor ID     Pri   State            Dead Time   Address         Interface  Instance ID
1.1.1.1              1   Full/DR          00:00:32      10.1.1.1           xe9/3       0
3.3.3.3              1   Full/Backup    00:00:40     20.1.1.2           xe17/1     0
 
 
R2#show bfd session
 
BFD process for VRF: (DEFAULT VRF)
================================================================================
Sess-Idx   Remote-Disc  Lower-Layer  Sess-Type   Sess-State  UP-Time   Interface   Down-Reason  Remote-Addr
1                  1                   IPv4              Single-Hop     Up          00:02:33     xe9/3            NA           10.1.1.1/32
2                  1                   IPv4              Single-Hop     Up          00:01:54     xe17/1          NA           20.1.1.2/32
Number of Sessions:    2
 
 
R2#show bfd session detail
 
BFD process for VRF: (DEFAULT VRF)
================================================================================
 
Session Interface Index : 10023          Interface name :xe9/3
Session Index : 1
Lower Layer : IPv4                            Version : 1
Session Type : Single Hop                Session State : Up
Local Discriminator : 1                     Local Address : 10.1.1.2/32
Remote Discriminator : 1                 Remote Address : 10.1.1.1/32
Local Port : 49152                            Remote Port : 3784
Options :
 
Diagnostics : None
 
Timers in Milliseconds :
Min Tx: 250                   Min Rx: 250                   Multiplier: 3
Neg Tx: 250                   Neg Rx: 250                   Neg detect mult: 3
Min echo Tx: 1000         Min echo Rx: 1000         Neg echo intrvl: 0
Storage type : 2
Sess down time : 00:00:00
Sess Down Reason : NA
Bfd GTSM Disabled
Bfd Authentication Disabled
 
Counters values:
Pkt In : 00000000000000000713                 Pkt Out : 00000000000000000714
Pkts Drop : 00000000000000000000           Auth Pkts Drop : 00000000000000000000
Echo Out : 00000000000000000000            IPv6 Echo Out : 00000000000000000000
IPv6 Pkt In : 00000000000000000000           IPv6 Pkt Out : 00000000000000000000
UP Count : 1                                                   UPTIME : 00:02:37
 
Protocol Client Info:
BGP-> Client ID: 44      Flags: 4
----------------------------------------------------------
 
Session Interface Index : 10053          Interface name :xe17/1
Session Index : 2
Lower Layer : IPv4                            Version : 1
Session Type : Single Hop                Session State : Up
Local Discriminator : 2                     Local Address : 20.1.1.1/32
Remote Discriminator : 1                 Remote Address : 20.1.1.2/32
Local Port : 49153                             Remote Port : 3784
Options :
 
Diagnostics : None
 
Timers in Milliseconds :
Min Tx: 250                   Min Rx: 250                    Multiplier: 3
Neg Tx: 250                   Neg Rx: 250                   Neg detect mult: 3
Min echo Tx: 1000         Min echo Rx: 1000         Neg echo intrvl: 0
Storage type : 2
Sess down time : 00:00:00
Sess Down Reason : NA
Bfd GTSM Disabled
Bfd Authentication Disabled
 
Counters values:
Pkt In : 00000000000000000535              Pkt Out : 00000000000000000537
Pkts Drop : 00000000000000000000           Auth Pkts Drop : 00000000000000000000
Echo Out : 00000000000000000000            IPv6 Echo Out : 00000000000000000000
IPv6 Pkt In : 00000000000000000000         IPv6 Pkt Out : 00000000000000000000
UP Count : 1                               UPTIME : 00:01:58
 
Protocol Client Info:
BGP-> Client ID: 44      Flags: 4
----------------------------------------------------------
Number of Sessions:    2
R3
R3#show ip ospf n
 
Total number of full neighbors: 1
OSPF process 100 VRF(default):
Neighbor ID     Pri   State            Dead Time   Address         Interface   Instance ID
2.2.2.2              1     Full/DR          00:00:36    20.1.1.1          xe17/10       0
 
 
R3#show bfd session
 
BFD process for VRF: (DEFAULT VRF)
================================================================================
Sess-Idx   Remote-Disc  Lower-Layer  Sess-Type   Sess-State  UP-Time   Interface   Down-Reason  Remote-Addr
1                        2            IPv4              Single-Hop       Up          00:01:21    xe17/1             NA           20.1.1.1/32
257                     1           IPv4              Multi-Hop              Up         00:00:00      xe6                 NA           1.1.1.1/32
Number of Sessions:    2
Total number of Established sessions 2
 
 
R3#show bfd session detail
 
BFD process for VRF: (DEFAULT VRF)
================================================================================
 
Session Interface Index : 10053          Interface name :xe17/1
Session Index : 1
Lower Layer : IPv4                            Version : 1
Session Type : Single Hop                Session State : Up
Local Discriminator : 1                     Local Address : 20.1.1.2/32
Remote Discriminator : 2                 Remote Address : 20.1.1.1/32
Local Port : 49152                            Remote Port : 3784
Options :
 
Diagnostics : None
 
Timers in Milliseconds :
Min Tx: 250                    Min Rx: 250                   Multiplier: 3
Neg Tx: 250                    Neg Rx: 250                   Neg detect mult: 3
Min echo Tx: 1000         Min echo Rx: 1000         Neg echo intrvl: 0
Storage type : 2
Sess down time : 00:00:00
Sess Down Reason : NA
Bfd GTSM Disabled
Bfd Authentication Disabled
 
Counters values:
Pkt In : 00000000000000000391                  Pkt Out : 00000000000000000391
Pkts Drop : 00000000000000000000           Auth Pkts Drop : 00000000000000000000
Echo Out : 00000000000000000000            IPv6 Echo Out : 00000000000000000000
IPv6 Pkt In : 00000000000000000000           IPv6 Pkt Out : 00000000000000000000
UP Count : 1                                                   UPTIME : 00:01:26
 
Protocol Client Info:
BGP-> Client ID: 44      Flags: 4
----------------------------------------------------------
 
Session Interface Index : 0                   Session Index : 257
Lower Layer : IPv4                                 Version : 1
Session Type : Multihop Arbit Path       Session State : Up
Local Discriminator : 257                      Local Address : 3.3.3.3/32
Remote Discriminator : 1                      Remote Address : 1.1.1.1/32
Local Port : 49153                                 Remote Port : 4784
Options :
 
Diagnostics : None
 
Timers in Milliseconds :
Min Tx: 250                        Min Rx: 250                    Multiplier: 3
Neg Tx: 250                        Neg Rx: 250                    Neg detect mult:250
Min echo Tx: 1000              Min echo Rx: 1000         Neg echo intrvl: 0
Storage type : 2
Sess down time : 00:00:00
Sess Down Reason : NA
Bfd GTSM Disabled
Bfd Authentication Disabled
 
Counters values:
Pkt In : 00000000000000000000                 Pkt Out : 00000000000000000047
Pkts Drop : 00000000000000000000           Auth Pkts Drop : 00000000000000000000
Echo Out : 00000000000000000000            IPv6 Echo Out : 00000000000000000000
IPv6 Pkt In : 00000000000000000000          IPv6 Pkt Out : 00000000000000000000
UP Count : 0                                                  UPTIME : 00:00:00
 
Protocol Client Info:
BGP-> Client ID: 44      Flags: 4
----------------------------------------------------------
Number of Sessions:    2
OSPF—BFD Multi-Hop Session
This section provides the steps for configuring BFD for OSPF multi-hop sessions.
Topology
 
Multi-hop OSPFv2 Topology
R1
 
| R1#configure terminal | Enter the Configure mode. | 
| R1(config)#interface lo  | Enter the Interface configuration mode for lo | 
| R1(config-if)#ip address 1.1.1.1/32 secondary | Assign IP Address | 
| R1(config)#interface eth1 | Enter the Interface configuration mode for eth1. | 
| R1(config-if)#ip address 10.1.1.1/24 | Assign IP Address | 
| R1(config-if)#exit | Exit the Interface configuration mode. | 
| R1(config)#interface eth2 | Enter the Interface configuration mode for eth1. | 
| R1(config-if)#ip address 30.1.1.1/24 | Assign IP Address | 
| R1(config-if)#exit | Exit the Interface configuration mode. | 
| R1(config)#router ospf 100 | Enter the Router mode for OSPF. | 
| R1(config-router)#ospf router-id 1.1.1.1 |  OSPF router ID in IPv4 format | 
| R1(config-router)#bfd all-interfaces | Enable BFD for all neighbors. | 
| R1(config-router)#network 10.1.1.0/24 area 1 | Advertise network 20.1.1.0/24 in OSPF area 1. | 
| R1(config-router)#network 1.1.1.1/32 area 1 | Advertise loopback network 1.1.1.1/32 in OSPF area 1. | 
| R1(config-router)#network 30.1.1.0/24 area 0 | Advertise network 30.1.1.0/24 in OSPF area 0. | 
| R1(config-router)#area 1 virtual-link 3.3.3.3 fall-over bfd | Create a virtual link to R3 with BFD. | 
| R1(config-router)#commit | Commit the configuration on the node | 
R2
 
| R2#configure terminal | Enter the Configure mode | 
| R2(config)#interface eth1 | Enter the Interface configuration mode for eth1. | 
| R2(config-if)#ip address 10.1.1.2/24 | Assign IP Address | 
| R2(config-if)#exit | Exit the Interface configuration mode. | 
| R2(config)#interface eth2 | Enter the Interface configuration mode for eth2. | 
| R2(config-if)#ip address 20.1.1.1/24 | Assign IP Address | 
| R2(config-if)#exit | Exit the Interface configuration mode | 
| R2(config)#interface lo | Enter the Interface configuration mode for lo | 
| R2(config-if)#ip address 2.2.2.2/32 secondary | Assign IP Address | 
| R2(config-if)#exit | Exit the Interface configuration mode | 
| R2(config)#router ospf 100 | Enter the Router mode for OSPF. | 
| R2(config-router)#bfd all-interfaces | Enable BFD for all neighbors. | 
| R2(config-router)#ospf router-id 2.2.2.2 | OSPF router ID in IPv4 format | 
| R2(config-router)#network 10.1.1.0/24 area 1 | Advertise network 10.1.1.0/24 in OSPF area 1. | 
| R2(config-router)#network 20.1.1.0/24 area 1 | Advertise network 20.1.1.0/24 in OSPF area 1. | 
| R2(config-router)#network 2.2.2.2/32 area 1 | Advertise loopback network 2.2.2.2/32 in OSPF area 1. | 
| R2(config-router)#commit | Commit the configuration on the node | 
| R2(config-router)#exit | Exit the router mode. | 
R3
 
| R3#configure terminal | Enter the Configure mode. | 
| R3(config)#interface lo | Enter the Interface configuration mode for lo | 
| R3(config-if)#ip address 3.3.3.3/32 secondary | Assign IP Address | 
| R3(config-if)#exit | Exit the Interface configuration mode. | 
| R3(config)#interface eth2 | Enter the Interface configuration mode for eth2. | 
| R3(config-if)#ip address 20.1.1.2/24 | Assign IP Address. | 
| R3(config-if)#exit | Exit the Interface configuration mode. | 
| R3(config)#router ospf 100 | Enter the Router mode for OSPF.  | 
| R3(config-router)#ospf router-id 3.3.3.3 | OSPF router ID in IPv4 format | 
| R3(config-router)#bfd all-interfaces | Enable BFD for all neighbors. | 
| R3(config-router)#network 20.1.1.0/24 area 1 | Advertise network 20.1.1.0/24 in OSPF area 1.  | 
| R3(config-router)#network 3.3.3.3/32 area 1 | Advertise loopback network 3.3.3.3/32 in OSPF area 1. | 
| R3(config-router)#area 1 virtual-link 1.1.1.1 fall-over bfd | Create a virtual link to R1 with BFD. | 
| R3(config-router)#commit | Commit the configuration on the node | 
Validation
R1#sh bfd session
 
BFD process for VRF: (DEFAULT VRF)
=====================================================================================
Sess-Idx   Remote-Disc  Lower-Layer  Sess-Type   Sess-State  UP-Time   Interface      Down-Reason  Remote-Addr
257              257                   IPv4         Multi-Hop         Up          00:00:54              NA         NA                    20.1.1.2/32
 
Number of Sessions:    1
 
 
R2#sh bfd session
 
BFD process for VRF: (DEFAULT VRF)
=====================================================================================
Sess-Idx   Remote-Disc  Lower-Layer  Sess-Type   Sess-State  UP-Time   Interface      Down-Reason  Remote-Addr
Number of Sessions:    0
 
 
 
R3#sh bfd session
 
BFD process for VRF: (DEFAULT VRF)
=====================================================================================
Sess-Idx   Remote-Disc  Lower-Layer  Sess-Type   Sess-State  UP-Time   Interface      Down-Reason  Remote-Addr
257        257          IPv4         Multi-Hop   Up          00:01:46  NA        NA           10.1.1.1/32
 
Number of Sessions:    1
 
 
R1#sh bfd session detail
 
BFD process for VRF: (DEFAULT VRF)
====================================================================================
 
Session Interface Index : 0              Session Index : 257
Lower Layer : IPv4                       Version : 1
Session Type : Multihop Arbit Path       Session State : Up
Local Discriminator : 257                Local Address : 10.1.1.1/32
Remote Discriminator : 257               Remote Address : 20.1.1.2/32
Local Port : 49152                       Remote Port : 4784
Options :
 
Diagnostics : None
 
Timers in Milliseconds :
Min Tx: 250               Min Rx: 250               Multiplier: 3
Neg Tx: 250               Neg Rx: 250               Neg detect mult: 3
Min echo Tx: 1000         Min echo Rx: 1000         Neg echo intrvl: 0
Storage type : 2
Sess down time : 00:00:00
Sess Down Reason : NA
Bfd GTSM Disabled
Bfd Authentication Disabled
 
Counters values:
Pkt In : 00000000000000000606              Pkt Out : 00000000000000000605
Pkts Drop : 00000000000000000000           Auth Pkts Drop : 00000000000000000000
Echo Out : 00000000000000000000            IPv6 Echo Out : 00000000000000000000
IPv6 Pkt In : 00000000000000000000         IPv6 Pkt Out : 00000000000000000000
UP Count : 1                               UPTIME : 00:02:13
 
Protocol Client Info:
OSPF-> Client ID: 4      Flags: 4
----------------------------------------------------------
Number of Sessions:    1
 
 
 
R2#sh bfd session detail
 
BFD process for VRF: (DEFAULT VRF)
====================================================================================
Number of Sessions:    0
R2#
 
 
R3#sh bfd session detail
 
BFD process for VRF: (DEFAULT VRF)
====================================================================================
 
Session Interface Index : 0              Session Index : 257
Lower Layer : IPv4                       Version : 1
Session Type : Multihop Arbit Path       Session State : Up
Local Discriminator : 257                Local Address : 20.1.1.2/32
Remote Discriminator : 257               Remote Address : 10.1.1.1/32
Local Port : 49152                       Remote Port : 4784
Options :
 
Diagnostics : None
 
Timers in Milliseconds :
Min Tx: 250               Min Rx: 250               Multiplier: 3
Neg Tx: 250               Neg Rx: 250               Neg detect mult: 3
Min echo Tx: 1000         Min echo Rx: 1000         Neg echo intrvl: 0
Storage type : 2
Sess down time : 00:00:00
Sess Down Reason : NA
Bfd GTSM Disabled
Bfd Authentication Disabled
 
Counters values:
Pkt In : 00000000000000000529              Pkt Out : 00000000000000000530
Pkts Drop : 00000000000000000000           Auth Pkts Drop : 00000000000000000000
Echo Out : 00000000000000000000            IPv6 Echo Out : 00000000000000000000
IPv6 Pkt In : 00000000000000000000         IPv6 Pkt Out : 00000000000000000000
UP Count : 1                               UPTIME : 00:01:56
 
Protocol Client Info:
OSPF-> Client ID: 4      Flags: 4
----------------------------------------------------------
Number of Sessions:    1
BFD Configuration in IS-IS
This section provides the steps for configuring BFD for the IS-IS protocol.
Topology
Basic Topology for BFD-ISIS 
R1
 
| R1#configure terminal | Enter the Configure mode. | 
| R1(config)#interface eth1 | Enter interface mode. | 
| R1(config-if)#ip address 10.1.1.1/24 | Configure IP address. | 
| R2(config-if)#ip router isis 1 | Configure ISIS router | 
| R1(config-if)#exit | Exit interface mode. | 
| R1(config)#router isis 1 | Enter the Router mode for IS-IS. | 
| R1(config-router)#net 10.0000.0000.0001.00 | Advertise network 10.0000.0000.0001.00 in IS-IS. | 
| R1(config-router)#bfd all-interfaces | Enable BFD for all neighbors. | 
| R1(config-router)#commit | Commit the configuration on the node | 
R2
 
| R2#configure terminal | Enter the Configure mode. | 
| R2(config)#interface eth1 | Enter interface mode. | 
| R2(config-if)#ip address 10.1.1.2/24 | Configure IP address. | 
| R2(config-if)#ip router isis 1 | Configure ISIS router | 
| R2(config-if)#exit | Exit interface mode. | 
| R2(config)#router isis 1 | Enter the Router mode for IS-IS. | 
| R2(config-router)#net 10.0000.0000.0002.00 | Advertise network 10.0000.0000.0002.00 in IS-IS. | 
| R2(config-router)#bfd all-interfaces | Enable BFD for all neighbors. | 
| R2(config-router)#commit | Commit the configuration on the node | 
Validation
R1#show bfd session
 
BFD process for VRF: (DEFAULT VRF)
=====================================================================================
Sess-Idx Remote-Disc Lower-Layer Sess-Type Sess-State UP-Time Interface    Down-Reason Remote-Addr
1                       1            IPv4              Single-Hop       Up          00:00:42      eth1           NA                    10.1.1.1/32
 
Number of Sessions:    1
 
R2#show bfd session
 
BFD process for VRF: (DEFAULT VRF)
=====================================================================================
Sess-Idx Remote-Disc Lower-Layer Sess-Type Sess-State UP-Time Interface      Down-Reason  Remote-Addr
1           1            IPv4    Single-Hop  Up  00:10:23      eth1           NA       10.1.1.2/32
1           1            IPv4    Single-Hop  Up  00:10:23      eth2           NA       20.1.1.2/32
Number of Sessions:    2
 
R1#show bfd session detail
======================================================
 
Session Interface Index : 3              
Interface name : eth1                    Session Index : 2
Lower Layer : IPv4                       Version : 1
Session Type : Single Hop                Session State : Up
Local Discriminator : 2                  Local Address : 10.1.1.1/32
Remote Discriminator : 3                 Remote Address : 10.1.1.2/32
Local Port : 49153                       Remote Port : 3784
Options :
 
Diagnostics : None
 
Timers in Milliseconds :
Min Tx: 250               Min Rx: 250               Multiplier: 3
Neg Tx: 250               Neg Rx: 2000              Neg detect mult: 3
Min echo Tx: 1000         Min echo Rx: 1000         Neg echo intrvl: 0
Storage type : 2
Sess down time : 00:00:00
Bfd GTSM Disabled
Bfd Authentication Disabled
 
Counters values:
Pkt In : 000000000000027b                Pkt Out : 0000000000000278
Echo Out : 0000000000000000              IPv6 Echo Out : 0000000000000000
IPv6 Pkt In : 0000000000000000           IPv6 Pkt Out : 0000000000000000
UP Count : 1                             UPTIME : 00:02:19
 
Protocol Client Info:
ISIS-> Client ID: 6      Flags: 4
----------------------------------------------------------
Number of Sessions:    1
 
R2#sh bfd session detail
======================================================
 
Session Interface Index : 3              
Interface name : eth1                    Session Index : 3
Lower Layer : IPv4                       Version : 1
Session Type : Single Hop                Session State : Up
Local Discriminator : 3                  Local Address : 10.1.1.2/32
Remote Discriminator : 2                 Remote Address : 10.1.1.1/32
Local Port : 49154                       Remote Port : 3784
Options :
 
Diagnostics : None
 
Timers in Milliseconds :
Min Tx: 250               Min Rx: 250               Multiplier: 3
Neg Tx: 250               Neg Rx: 250               Neg detect mult: 3
Min echo Tx: 1000         Min echo Rx: 1000         Neg echo intrvl: 0
Storage type : 2
Sess down time : 00:00:00
Bfd GTSM Disabled
Bfd Authentication Disabled
 
Counters values:
Pkt In : 00000000000002db                Pkt Out : 00000000000002dd
Echo Out : 0000000000000000              IPv6 Echo Out : 0000000000000000
IPv6 Pkt In : 0000000000000000           IPv6 Pkt Out : 0000000000000000
UP Count : 1                             UPTIME : 00:02:42
 
Protocol Client Info:
ISIS-> Client ID: 6      Flags: 4
----------------------------------------------------------
Number of Sessions:    1
BFD Configuration in BGP
This section provides the steps for configuring BFD for the BGP protocol.
Topology
Basic Topology for BFD in BGP
R1
 
| R1#configure terminal  | Enter configure mode  | 
| R1(config)#interface eth1 | Enter the Interface configuration mode for eth1. | 
| R1(config-if)#ip address 10.1.1.1/24 | Assign IP Address | 
| R1(config-if)#exit | Exit the Interface configuration mode. | 
| R1(config)# interface lo | Enter interface mode  | 
| R1(config-if)#ip address 1.1.1.1/32 secondary | Configure the IP address on loopback interface. | 
| R1(config-if)#bfd session  1.1.1.1  3.3.3.3 multihop | Enable BFD multihop session | 
| R1(config)#router ospf 100 | Enter Router mode for OSPF | 
| R1(config-router)# ospf router-id 1.1.1.1 | Configure router-id in OSPF | 
| R1(config-router)# network 1.1.1.1/32 area 0.0.0.1 | Advertise network 1.1.1.1/32 in OSPF area 1. | 
| R1(config-router)# network 10.1.1.0/24 area 0.0.0.1  | Advertise network 10.1.1.0/24 in OSPF area 1. | 
| R1(config)#router bgp 100 | Enter Router mode for BGP | 
| R1(config-router)# neighbor 3.3.3.3 remote-as 100 | Add the neighbor 3.3.3.3 to remote-as 100. | 
| R1(config-router)# neighbor 3.3.3.3 fall-over bfd  | Enable BFD option for neighbor multihop | 
| R1(config-router)#neighbor 3.3.3.3 update-source lo | Add neighbor 3.3.3.3 to update-source lo. | 
| R1(config-router)#neighbor 10.1.1.2 remote-as 100 | Add neighbor 10.1.1.2 to remote-as 100. | 
| R1(config-router)# neighbor 10.1.1.2 fall-over bfd | Enable BFD option for neighbor | 
| R1(config-router)#commit | Commit the configuration on the node | 
| R1(config-router)#end | Exit from Router BGP mode | 
R2
 
| R2#configure terminal | Enter configure mode  | 
| R2(config)#interface eth1 | Enter the Interface configuration mode for eth1. | 
| R2(config-if)#ip address 10.1.1.2/24 | Assign IP Address | 
| R2(config-if)#exit | Exit the Interface configuration mode. | 
| R2(config)#interface eth2 | Enter the Interface configuration mode for eth2. | 
| R2(config-if)#ip address 20.1.1.1/24 | Assign IP Address | 
| R2(config-if)#exit | Exit the Interface configuration mode | 
| R2(config)# interface lo | Enter interface mode  | 
| R2(config-if)#ip address 2.2.2.2/32 secondary | Configure the IP address on loopback interface. | 
| R2(config-if)#exit | Exit the Interface configuration mode | 
| R2(config)#router ospf 100 | Enter Router mode for OSPF | 
| R2(config-router)#ospf router-id 2.2.2.2 | Configure router-id in OSPF | 
| R2(config-router)# network 2.2.2.2/32 area 0.0.0.1 | Advertise network 1.1.1.1/32 in OSPF area 1. | 
| R2(config-router)#network 10.1.1.0/24 area 0.0.0.1 | Advertise network 10.1.1.0/24 in OSPF area 1. | 
| R2(config-router)# network 20.1.1.0/24 area 0.0.0.1 | Advertise network 20.1.1.0/24 in OSPF area 1. | 
| R3(config-router)#exit | Exit from Router OSPF mode | 
| R2(config)#router bgp 100 | Enter Router mode for BGP | 
| R2(config-router)# neighbor 10.1.1.1 remote-as 100 | Add neighbor 10.1.1.1 to remote-as 100. | 
| R2(config-router)#neighbor 10.1.1.1 fall-over bfd | Enable BFD option for neighbor | 
| R2(config-router)# neighbor 20.1.1.2 remote-as 100 | Add neighbor 20.1.1.2 to remote-as 100. | 
| R2(config-router)# neighbor 20.1.1.2 fall-over bfd | Enable BFD option for neighbor | 
| R2(config-router)#commit | Commit the configuration on the node | 
| R2(config-router)#end | Exit from Router BGP mode | 
R3
 
| R3#configure terminal | Enter configure mode  | 
| R3(config)#interface eth2 | Enter the Interface configuration mode for eth2. | 
| R3(config-if)#ip address 20.1.1.2/24 | Assign IP Address. | 
| R3(config-if)#exit | Exit the Interface configuration mode. | 
| R3(config)# interface lo | Enter interface mode  | 
| R3(config-if)#ip address 3.3.3.3/32 secondary | Configure IP address on loopback interface. | 
| R1(config-if)#bfd session 3.3.3.3 1.1.1.1 multihop  | Enable BFD multihop session | 
| R2(config-if)#exit | Exit the Interface configuration mode | 
| R3(config)#router ospf 100 | Enter Router mode for OSPF | 
| R3(config-router)#ospf router-id 3.3.3.3 | Configure router-id in OSPF | 
| R3(config-router)# network 3.3.3.3/32 area 0.0.0.1 | Advertise network 3.3.3.3/32 in OSPF area 1. | 
| R3(config-router)# network 20.1.1.0/24 area 0.0.0.1 | Advertise network 20.1.1.0/24 in OSPF area 1. | 
| R3(config-router)#exit | Exit from Router OSPF mode | 
| R3(config)#router bgp 100 | Enter Router mode for BGP | 
| R3(config-router)# neighbor 1.1.1.1 remote-as 100 | Add neighbor 1.1.1.1 to remote-as 100. | 
| R3(config-router)# neighbor 1.1.1.1 fall-over bfd multihop | Enable BFD option for neighbor | 
| R3(config-router)#neighbor 1.1.1.1 update-source lo | Add neighbor 1.1.1.1 to update-source lo. | 
| R3(config-router)# neighbor 20.1.1.1 remote-as 100 | Add neighbor 20.1.1.1 to remote-as 100. | 
| R3(config-router)#neighbor 20.1.1.1 fall-over bfd | Enable BFD option for neighbor | 
| R3(config-router)#commit | Commit the configuration on the node | 
| R3(config-router)#end | Exit from Router BGP mode | 
Validation
R1
R1#show ip ospf neighbor
 
Total number of full neighbors: 1
OSPF process 100 VRF(default):
Neighbor ID     Pri   State            Dead Time   Address         Interface   Instance ID
2.2.2.2             1   Full/Backup      00:00:35    10.1.1.2            eth1         0
R1#show bfd session
 
BFD process for VRF: (DEFAULT VRF)
================================================================================
=====
Sess-Idx   Remote-Disc  Lower-Layer  Sess-Type   Sess-State  UP-Time   Interface  Down-Reason  Remote-Addr
1                        1                 IPv4         Single-Hop      Up          00:02:55       eth1      NA                   10.1.1.2/32
257                    0                 IPv4         Multi-Hop       Up           00:00:18      NA         NA                    3.3.3.3/32
Number of Sessions:    2
 
 
R1#show bfd session detail
 
BFD process for VRF: (DEFAULT VRF)
================================================================================
====
 
Session Interface Index : 10023          Interface name :eth1
Session Index : 1
Lower Layer : IPv4                                 Version : 1
Session Type : Single Hop                     Session State : Up
Local Discriminator : 1                          Local Address : 10.1.1.1/32
Remote Discriminator : 1                      Remote Address : 10.1.1.2/32
Local Port : 49152                                 Remote Port : 3784
Options :
 
Diagnostics : None
 
Timers in Milliseconds :
Min Tx: 250                    Min Rx: 250                    Multiplier: 3
Neg Tx: 250                    Neg Rx: 250                    Neg detect mult: 3
Min echo Tx: 1000          Min echo Rx: 1000         Neg echo intrvl: 0
Storage type : 2
Sess down time : 00:00:00
Sess Down Reason : NA
Bfd GTSM Disabled
Bfd Authentication Disabled
 
Counters values:
Pkt In : 00000000000000000814                  Pkt Out : 00000000000000000814
Pkts Drop : 00000000000000000000           Auth Pkts Drop : 00000000000000000000
Echo Out : 00000000000000000000            IPv6 Echo Out : 00000000000000000000
IPv6 Pkt In : 00000000000000000000           IPv6 Pkt Out : 00000000000000000000
UP Count : 1                                                    UPTIME : 00:02:59
 
Protocol Client Info:
BGP-> Client ID: 44      Flags: 4
----------------------------------------------------------
 
Session Interface Index : 0                    Session Index : 257
Lower Layer : IPv4                                 Version : 1
Session Type : Multihop Arbit Path       Session State : Up
Local Discriminator : 257                      Local Address : 1.1.1.1/32
Remote Discriminator : 0                      Remote Address : 3.3.3.3/32
Local Port : 49153                                  Remote Port : 4784
Options :
 
Diagnostics : None
 
Timers in Milliseconds :
Min Tx: 250                   Min Rx: 250                   Multiplier: 3
Neg Tx: 0                       Neg Rx: 0                       Neg detect mult: 0
Min echo Tx: 1000         Min echo Rx: 1000         Neg echo intrvl: 0
Storage type : 2
Sess down time : 00:00:00
Sess Down Reason : NA
Bfd GTSM Disabled
Bfd Authentication Disabled
 
Counters values:
Pkt In : 00000000000000000000                 Pkt Out : 00000000000000000107
Pkts Drop : 00000000000000000000           Auth Pkts Drop : 00000000000000000000
Echo Out : 00000000000000000000            IPv6 Echo Out : 00000000000000000000
IPv6 Pkt In : 00000000000000000000          IPv6 Pkt Out : 00000000000000000000
UP Count : 0                                                  UPTIME : 00:00:00
R2
R2#show ip ospf neighbor
 
Total number of full neighbors: 2
OSPF process 100 VRF(default):
Neighbor ID     Pri   State            Dead Time   Address         Interface  Instance ID
1.1.1.1              1   Full/DR          00:00:32      10.1.1.1           eth1         0
3.3.3.3              1   Full/Backup    00:00:40     20.1.1.2           eth2         0
 
 
R2#show bfd session
 
BFD process for VRF: (DEFAULT VRF)
================================================================================
=====
Sess-Idx   Remote-Disc  Lower-Layer  Sess-Type   Sess-State  UP-Time   Interface   Down-Reason  Remote-Addr
1                  1                   IPv4              Single-Hop     Up          00:02:33     eth1            NA               10.1.1.1/32
2                  1                   IPv4              Single-Hop     Up          00:01:54     eth2            NA               20.1.1.2/32
Number of Sessions:    2
 
 
R2#show bfd session detail
 
BFD process for VRF: (DEFAULT VRF)
================================================================================
====
 
Session Interface Index : 10023          Interface name :eth1
Session Index : 1
Lower Layer : IPv4                            Version : 1
Session Type : Single Hop                Session State : Up
Local Discriminator : 1                     Local Address : 10.1.1.2/32
Remote Discriminator : 1                 Remote Address : 10.1.1.1/32
Local Port : 49152                            Remote Port : 3784
Options :
 
Diagnostics : None
 
Timers in Milliseconds :
Min Tx: 250                   Min Rx: 250                   Multiplier: 3
Neg Tx: 250                   Neg Rx: 250                   Neg detect mult: 3
Min echo Tx: 1000         Min echo Rx: 1000         Neg echo intrvl: 0
Storage type : 2
Sess down time : 00:00:00
Sess Down Reason : NA
Bfd GTSM Disabled
Bfd Authentication Disabled
 
Counters values:
Pkt In : 00000000000000000713                 Pkt Out : 00000000000000000714
Pkts Drop : 00000000000000000000           Auth Pkts Drop : 00000000000000000000
Echo Out : 00000000000000000000            IPv6 Echo Out : 00000000000000000000
IPv6 Pkt In : 00000000000000000000           IPv6 Pkt Out : 00000000000000000000
UP Count : 1                                                   UPTIME : 00:02:37
 
Protocol Client Info:
BGP-> Client ID: 44      Flags: 4
----------------------------------------------------------
 
Session Interface Index : 10053          Interface name :eth2
Session Index : 2
Lower Layer : IPv4                            Version : 1
Session Type : Single Hop                Session State : Up
Local Discriminator : 2                     Local Address : 20.1.1.1/32
Remote Discriminator : 1                 Remote Address : 20.1.1.2/32
Local Port : 49153                             Remote Port : 3784
Options :
 
Diagnostics : None
 
Timers in Milliseconds :
Min Tx: 250                   Min Rx: 250                    Multiplier: 3
Neg Tx: 250                   Neg Rx: 250                   Neg detect mult: 3
Min echo Tx: 1000         Min echo Rx: 1000         Neg echo intrvl: 0
Storage type : 2
Sess down time : 00:00:00
Sess Down Reason : NA
Bfd GTSM Disabled
Bfd Authentication Disabled
 
Counters values:
Pkt In : 00000000000000000535              Pkt Out : 00000000000000000537
Pkts Drop : 00000000000000000000           Auth Pkts Drop : 00000000000000000000
Echo Out : 00000000000000000000            IPv6 Echo Out : 00000000000000000000
IPv6 Pkt In : 00000000000000000000         IPv6 Pkt Out : 00000000000000000000
UP Count : 1                               UPTIME : 00:01:58
 
Protocol Client Info:
BGP-> Client ID: 44      Flags: 4
----------------------------------------------------------
Number of Sessions:    2
R3
R3#show ip ospf neighbor
 
Total number of full neighbors: 1
OSPF process 100 VRF(default):
Neighbor ID     Pri   State            Dead Time   Address         Interface   Instance ID
2.2.2.2              1     Full/DR          00:00:36    20.1.1.1          eth1             0
 
 
R3#show bfd session
 
BFD process for VRF: (DEFAULT VRF)
================================================================================
=====
Sess-Idx   Remote-Disc  Lower-Layer  Sess-Type   Sess-State  UP-Time   Interface   Down-Reason  Remote-Addr
1                        2            IPv4              Single-Hop       Up          00:01:21    eth1            NA                20.1.1.1/32
257                     1           IPv4              Multi-Hop        Up         00:00:00      NA              NA                1.1.1.1/32
Number of Sessions:    2
Total number of Established sessions 2
 
 
R3#show bfd session detail
 
BFD process for VRF: (DEFAULT VRF)
================================================================================
====
 
Session Interface Index : 10053          Interface name :eth1
Session Index : 1
Lower Layer : IPv4                            Version : 1
Session Type : Single Hop                Session State : Up
Local Discriminator : 1                     Local Address : 20.1.1.2/32
Remote Discriminator : 2                 Remote Address : 20.1.1.1/32
Local Port : 49152                            Remote Port : 3784
Options :
 
Diagnostics : None
 
Timers in Milliseconds :
Min Tx: 250                    Min Rx: 250                   Multiplier: 3
Neg Tx: 250                    Neg Rx: 250                   Neg detect mult: 3
Min echo Tx: 1000         Min echo Rx: 1000         Neg echo intrvl: 0
Storage type : 2
Sess down time : 00:00:00
Sess Down Reason : NA
Bfd GTSM Disabled
Bfd Authentication Disabled
 
Counters values:
Pkt In : 00000000000000000391                  Pkt Out : 00000000000000000391
Pkts Drop : 00000000000000000000           Auth Pkts Drop : 00000000000000000000
Echo Out : 00000000000000000000            IPv6 Echo Out : 00000000000000000000
IPv6 Pkt In : 00000000000000000000           IPv6 Pkt Out : 00000000000000000000
UP Count : 1                                                   UPTIME : 00:01:26
 
Protocol Client Info:
BGP-> Client ID: 44      Flags: 4
----------------------------------------------------------
 
Session Interface Index : 0                   Session Index : 257
Lower Layer : IPv4                                 Version : 1
Session Type : Multihop Arbit Path       Session State : Up
Local Discriminator : 257                      Local Address : 3.3.3.3/32
Remote Discriminator : 1                      Remote Address : 1.1.1.1/32
Local Port : 49153                                 Remote Port : 4784
Options :
 
Diagnostics : None
 
Timers in Milliseconds :
Min Tx: 250                        Min Rx: 250                    Multiplier: 3
Neg Tx: 250                        Neg Rx: 250                    Neg detect mult:250
Min echo Tx: 1000              Min echo Rx: 1000         Neg echo intrvl: 0
Storage type : 2
Sess down time : 00:00:00
Sess Down Reason : NA
Bfd GTSM Disabled
Bfd Authentication Disabled
 
Counters values:
Pkt In : 00000000000000000000                 Pkt Out : 00000000000000000047
Pkts Drop : 00000000000000000000           Auth Pkts Drop : 00000000000000000000
Echo Out : 00000000000000000000            IPv6 Echo Out : 00000000000000000000
IPv6 Pkt In : 00000000000000000000          IPv6 Pkt Out : 00000000000000000000
UP Count : 0                                                  UPTIME : 00:00:00
 
Protocol Client Info:
BGP-> Client ID: 44      Flags: 4
----------------------------------------------------------
Number of Sessions:    2