配置VRRP与BFD联动实现快速切换
组网需求
如图1所示,局域网内的主机通过Switch双归属到部署了VRRP备份组的RouterA和RouterB,其中RouterA为Master。
用户希望当RouterA或RouterA到Switch间链路出现故障时,主备网关间的切换时间小于1秒,以减少故障对业务传输的影响。
图1 配置VRRP与BFD联动实现快速切换组网图
配置思路
采用VRRP与BFD联动实现主备网关间的快速切换,配置思路如下:
- 配置各设备接口IP地址及路由协议,使网络层路由可达。
- 在RouterA和RouterB上配置VRRP备份组,其中RouterA的优先级为120,抢占延时为20秒,作为Master设备;RouterB的优先级为缺省值,作为Backup设备,实现网关的主备备份。
- 在RouterA和RouterB上配置静态BFD会话,监测备份组之间的链路。
- 在RouterB上配置VRRP与BFD联动,实现链路故障时VRRP备份组快速切换。
操作步骤
- 配置设备间的网络互连
1. # 配置设备各接口的IP地址和路由协议,以RouterA为例。RouterB的配置与RouterA类似,详见配置文件。 <Huawei> system-view
[Huawei] sysname RouterA
[RouterA] interface gigabitethernet 2/0/0
[RouterA-GigabitEthernet2/0/0] ip address 10.1.1.1 24
[RouterA-GigabitEthernet2/0/0] quit
[RouterA] ospf
[RouterA-ospf-1] area 0
[RouterA-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[RouterA-ospf-1-area-0.0.0.0] quit
[RouterA-ospf-1] quit
- 配置VRRP备份组
1. # 在RouterA上创建VRRP备份组1,配置RouterA在该备份组中的优先级为120,并配置抢占延时为20秒。 [RouterA] interface gigabitethernet 2/0/0
[RouterA-GigabitEthernet2/0/0] vrrp vrid 1 virtual-ip 10.1.1.3
[RouterA-GigabitEthernet2/0/0] vrrp vrid 1 priority 120
[RouterA-GigabitEthernet2/0/0] vrrp vrid 1 preempt-mode timer delay 20
[RouterA-GigabitEthernet2/0/0] quit # 在RouterB上创建VRRP备份组1,其在该备份组中的优先级为缺省值100。 [RouterB] interface gigabitethernet 2/0/0
[RouterB-GigabitEthernet2/0/0] vrrp vrid 1 virtual-ip 10.1.1.3
[RouterB-GigabitEthernet2/0/0] quit
- 配置静态BFD会话
# 在RouterA上配置BFD会话。 [RouterA] bfd
[RouterA-bfd] quit
[RouterA] bfd atob bind peer-ip 10.1.1.2 interface gigabitethernet 2/0/0
[RouterA-bfd-session-atob] discriminator local 1
[RouterA-bfd-session-atob] discriminator remote 2
[RouterA-bfd-session-atob] min-rx-interval 50
[RouterA-bfd-session-atob] min-tx-interval 50
[RouterA-bfd-session-atob] commit
[RouterA-bfd-session-atob] quit # 在RouterB上配置BFD会话。 [RouterB] bfd
[RouterB-bfd] quit
[RouterB] bfd btoa bind peer-ip 10.1.1.1 interface gigabitethernet 2/0/0
[RouterB-bfd-session-btoa] discriminator local 2
[RouterB-bfd-session-btoa] discriminator remote 1
[RouterB-bfd-session-btoa] min-rx-interval 50
[RouterB-bfd-session-btoa] min-tx-interval 50
[RouterB-bfd-session-btoa] commit
- [RouterB-bfd-session-btoa] quit 配置完成后,在RouterA或RouterB上执行display bfd session命令,可以看到BFD会话的状态为Up。以RouterA的显示为例。
1. [RouterA] display bfd session all
--------------------------------------------------------------------------------
Local Remote PeerIpAddr State Type InterfaceName
--------------------------------------------------------------------------------
1 2 10.1.1.2 Up S_IP_IF GigabitEthernet1/0/0
--------------------------------------------------------------------------------
Total UP/DOWN Session Number : 1/0
- 配置VRRP与BFD联动功能
1. # 在RouterB上配置VRRP与BFD联动,当BFD会话状态Down时,RouterB的优先级增加40。 [RouterB] interface gigabitethernet 2/0/0
[RouterB-GigabitEthernet2/0/0] vrrp vrid 1 track bfd-session 2 increased 40
[RouterB-GigabitEthernet2/0/0] quit
- 验证配置结果 # 完成上述配置后,在RouterA和RouterB上分别执行display vrrp命令,可以看出RouterA为Master设备,RouterB为Backup设备,联动的BFD会话状态为UP。
[RouterA] display vrrp
GigabitEthernet2/0/0 | Virtual Router 1
State : Master
Virtual IP : 10.1.1.3
Master IP : 10.1.1.1
PriorityRun : 120
PriorityConfig : 120
MasterPriority : 120
Preempt : YES Delay Time : 20 s
TimerRun : 1 s
TimerConfig : 1 s
Auth Type : NONE
Virtual Mac : 0000-5e00-0101
Check TTL : YES
Config type : normal-vrrp
Backup-forward : disabled
Create time : 2012-05-22 17:32:56
Last change time : 2012-05-22 17:33:00 [RouterB] display vrrp
GigabitEthernet2/0/0 | Virtual Router 1
State : Backup
Virtual IP : 10.1.1.3
Master IP : 10.1.1.1
PriorityRun : 100
PriorityConfig : 100
MasterPriority : 120
Preempt : YES Delay Time : 0 s
TimerRun : 1 s
TimerConfig : 1 s
Auth Type : NONE
Virtual Mac : 0000-5e00-0101
Check TTL : YES
Config type : normal-vrrp
Backup-forward : disabled
Track BFD : 2 Priority increased : 40
BFD-Session State: UP
Create time : 2012-05-22 17:33:00
- Last change time : 2012-05-22 17:33:04 # 在RouterA的接口GE2/0/0上执行shutdown命令,模拟链路故障。此时在RouterA和RouterB上分别执行display vrrp命令,可以看出RouterA状态变为Initialize,RouterB状态变为Master,联动的BFD会话状态为DOWN。
[RouterA] interface gigabitethernet 2/0/0
[RouterA-GigabitEthernet2/0/0] shutdown
[RouterA-GigabitEthernet2/0/0] quit [RouterA] display vrrp
GigabitEthernet2/0/0 | Virtual Router 1
State : Initialize
Virtual IP : 10.1.1.3
Master IP : 0.0.0.0
PriorityRun : 120
PriorityConfig : 120
MasterPriority : 0
Preempt : YES Delay Time : 20 s
TimerRun : 1 s
TimerConfig : 1 s
Auth Type : NONE
Virtual Mac : 0000-5e00-0101
Check TTL : YES
Config type : normal-vrrp
Backup-forward : disabled
Create time : 2012-05-22 17:32:56
Last change time : 2012-05-22 17:33:06 [RouterB] display vrrp
GigabitEthernet2/0/0 | Virtual Router 1
State : Master
Virtual IP : 10.1.1.3
Master IP : 10.1.1.2
PriorityRun : 140
PriorityConfig : 100
MasterPriority : 140
Preempt : YES Delay Time : 0 s
TimerRun : 1 s
TimerConfig : 1 s
Auth Type : NONE
Virtual Mac : 0000-5e00-0101
Check TTL : YES
Config type : normal-vrrp
Backup-forward : disabled
Track BFD : 2 Priority increased : 40
BFD-Session State: DOWN
Create time : 2012-05-22 17:33:00
- Last change time : 2012-05-22 17:33:06 # 在RouterA的接口GE2/0/0上执行undo shutdown命令,模拟故障恢复。20秒后,分别在RouterA和RouterB上执行display vrrp命令,可以看出RouterA状态恢复为Master,RouterB状态恢复为Backup,联动的BFD会话状态恢复为UP。 [RouterA]
5. interface gigabitethernet 2/0/0
[RouterA-GigabitEthernet2/0/0] undo shutdown
[RouterA-GigabitEthernet2/0/0] quit [RouterA] display vrrp
GigabitEthernet2/0/0 | Virtual Router 1
State : Master
Virtual IP : 10.1.1.3
Master IP : 10.1.1.1
PriorityRun : 120
PriorityConfig : 120
MasterPriority : 120
Preempt : YES Delay Time : 20 s
TimerRun : 1 s
TimerConfig : 1 s
Auth Type : NONE
Virtual Mac : 0000-5e00-0101
Check TTL : YES
Config type : normal-vrrp
Backup-forward : disabled
Create time : 2012-05-22 17:32:56
Last change time : 2012-05-22 17:33:50 [RouterB] display vrrp
GigabitEthernet2/0/0 | Virtual Router 1
State : Backup
Virtual IP : 10.1.1.3
Master IP : 10.1.1.1
PriorityRun : 100
PriorityConfig : 100
MasterPriority : 120
Preempt : YES Delay Time : 0 s
TimerRun : 1 s
TimerConfig : 1 s
Auth Type : NONE
Virtual Mac : 0000-5e00-0101
Check TTL : YES
Config type : normal-vrrp
Backup-forward : disabled
Track BFD : 2 Priority increased : 40
BFD-Session State: UP
Create time : 2012-05-22 17:33:00
Last change time : 2012-05-22 17:33:50
配置文件
- RouterA的配置文件 #
• sysname RouterA
#
bfd
#
interface GigabitEthernet2/0/0
ip address 10.1.1.1 255.255.255.0
vrrp vrid 1 virtual-ip 10.1.1.3
vrrp vrid 1 priority 120
vrrp vrid 1 preempt-mode timer delay 20
#
bfd atob bind peer-ip 10.1.1.2 interface GigabitEthernet2/0/0
discriminator local 1
discriminator remote 2
min-tx-interval 50
min-rx-interval 50
commit
#
return
• RouterB的配置文件 #
sysname RouterB
#
bfd
#
interface GigabitEthernet2/0/0
ip address 10.1.1.2 255.255.255.0
vrrp vrid 1 virtual-ip 10.1.1.3
vrrp vrid 1 track bfd-session 2 increased 40
#
bfd btoa bind peer-ip 10.1.1.1 interface GigabitEthernet2/0/0
discriminator local 2
discriminator remote 1
min-tx-interval 50
min-rx-interval 50
commit
#
return