华为RIP与BFD联动实验

双向转发检测BFD是一种用于检测邻居路由之间链路故障的检测机制，他通常与路由协议联动，通过快速感知链路故障并通告使得路由协议能够快速的重新收敛，从而减少由于拓扑变化导致的流量丢失。

查看邻居建立关系

[R1]disrip1neighbor
---------------------------------------------------------------------
IPAddressInterfaceTypeLast-Heard-Time
---------------------------------------------------------------------
192.168.1.1GigabitEthernet0/0/1RIP015
NumberofRIProutes:2
192.168.2.1GigabitEthernet0/0/2RIP013
NumberofRIProutes:1

查看路由表，发现去往172.16.1.0/24下一跳是 192.168.1.1 接口是g0/0/1

[R1]disiprouting-table
RouteFlags:R-relay,D-downloadtofib
------------------------------------------------------------------------------
RoutingTables:Public
Destinations:12Routes:13

Destination/MaskProtoPreCostFlagsNextHopInterface

127.0.0.0/8Direct00D127.0.0.1InLoopBack0
127.0.0.1/32Direct00D127.0.0.1InLoopBack0
127.255.255.255/32Direct00D127.0.0.1InLoopBack0
172.16.1.0/24RIP1001D192.168.1.1GigabitEthernet0/0/1
192.168.1.0/24Direct00D192.168.1.2GigabitEthernet0/0/1
192.168.1.2/32Direct00D127.0.0.1GigabitEthernet0/0/1
192.168.1.255/32Direct00D127.0.0.1GigabitEthernet0/0/1
192.168.2.0/24Direct00D192.168.2.2GigabitEthernet0/0/2
192.168.2.2/32Direct00D127.0.0.1GigabitEthernet0/0/2
192.168.2.255/32Direct00D127.0.0.1GigabitEthernet0/0/2
192.168.3.0/24RIP1001D192.168.2.1GigabitEthernet0/0/2
RIP1001D192.168.1.1GigabitEthernet0/0/1
255.255.255.255/32Direct00D127.0.0.1InLoopBack0

R1启用BFD

[R1]bfd
[R1-bfd]quit
[R1]rip1
[R1-rip-1]bfdall
[R1-rip-1]bfdall-interfacesenable
[R1-rip-1]bfdall-interfacesmin-rx-interval100min-tx-interval100detect-multiplier10
[R1-rip-1]quit

R2启用BFD

[R2]bfd
[R2-bfd]quit
[R2]rip1
[R2-rip-1]bfdall
[R2-rip-1]bfdall-interfacesenable
[R2-rip-1]bfdall-interfacesmin-rx-interval100min-tx-interval100detect-multiplier10
[R2-rip-1]quit

查看BFD，发现R1与R2已经建立成功

[R1]disrip1bfdsessionall
LocalIp:192.168.1.2RemoteIp:192.168.1.1BFDState:Up
TX:100RX:100Multiplier:10
BFDLocalDis:8192Interface:GigabitEthernet0/0/1
DiagnosticInfo:Nodiagnosticinformation

LocalIp:192.168.2.2RemoteIp:192.168.2.1BFDState:Down
TX:13999RX:13999Multiplier:0
BFDLocalDis:8193Interface:GigabitEthernet0/0/2
DiagnosticInfo:Nodiagnosticinformation

手动关闭R2上面连接R1的接口，再次查看bfd发现不存在了

[R1]disrip1bfdsessionall
LocalIp:192.168.2.2RemoteIp:192.168.2.1BFDState:Down
TX:13999RX:13999Multiplier:0
BFDLocalDis:8193Interface:GigabitEthernet0/0/2
DiagnosticInfo:Nodiagnosticinformation

再次查看路由表，发现去往172.16.1.0/24的下一跳更改了

[R1]disiprouting-table
RouteFlags:R-relay,D-downloadtofib
------------------------------------------------------------------------------
RoutingTables:Public
Destinations:9Routes:9

Destination/MaskProtoPreCostFlagsNextHopInterface

127.0.0.0/8Direct00D127.0.0.1InLoopBack0
127.0.0.1/32Direct00D127.0.0.1InLoopBack0
127.255.255.255/32Direct00D127.0.0.1InLoopBack0
172.16.1.0/24RIP1002D192.168.2.1GigabitEthernet0/0/2
192.168.2.0/24Direct00D192.168.2.2GigabitEthernet0/0/2
192.168.2.2/32Direct00D127.0.0.1GigabitEthernet0/0/2
192.168.2.255/32Direct00D127.0.0.1GigabitEthernet0/0/2
192.168.3.0/24RIP1001D192.168.2.1GigabitEthernet0/0/2
255.255.255.255/32Direct00D127.0.0.1InLoopBack0