实验目的

       企业出口网关设备故障通过VRRP BFD联动快速切换

实验过程

1. AR1与AR2运行VRRP协议，作为VLAN 10和VLAN 20的网关

2. AR1与AR2通过设备优先级让设备互为主备，提高网络冗余性

3. AR1作为VLAN 10的主网关，AR2作为VLAN 20的主网关

4. 在AR1和AR2上配置NAT和必要的路由

5. PC机可以与8.8.8.8地址通信

6. 当 SW2 与 R3 之间的链路故障时， R1 无法感知，会导致网关不切换为了进一步

提高可靠性，要求配置BFD联动VRRP，当上联链路失效后，流量能够切换到另一台

设备。

在交换机上创建 VLAN 并划分接口

[SW1] vlan batch 10 20

[SW1] interface g0/0/1

[SW1-GigabitEthernet0/0/1] port link-type trunk

[SW1-GigabitEthernet0/0/1] port trunk allow-pass vlan 10 20

[SW1-GigabitEthernet0/0/1] interface g0/0/2

[SW1-GigabitEthernet0/0/2] port link-type trunk

[SW1-GigabitEthernet0/0/2] port trunk allow-pass vlan 10 20

[SW1-GigabitEthernet0/0/2] interface g0/0/3

[SW1-GigabitEthernet0/0/3] port link-type access

[SW1-GigabitEthernet0/0/3] port default vlan 10

[SW1-GigabitEthernet0/0/3] interface g0/0/4

[SW1-GigabitEthernet0/0/4] port link-type access

[SW1-GigabitEthernet0/0/4] port default vlan 20

配置AR

AR1

[AR1] interface g0/0/1.10

[AR1-GigabitEthernet0/0/1.10] ip address 192.168.10.252 24

[AR1-GigabitEthernet0/0/1.10] dot1q termination vid 10

[AR1-GigabitEthernet0/0/1.10] arp broadcast enable

[AR1-GigabitEthernet0/0/1.10] vrrp vrid 10 virtual-ip 192.168.10.254

[AR1-GigabitEthernet0/0/1.10] vrrp vrid 10 priority 200

[AR1-GigabitEthernet0/0/1.10] interface g0/0/1.20

[AR1-GigabitEthernet0/0/1.20] ip address 192.168.20.252 24

[AR1-GigabitEthernet0/0/1.20] dot1q termination vid 20

[AR1-GigabitEthernet0/0/1.20] arp broadcast enable

[AR1-GigabitEthernet0/0/1.20] vrrp vrid 20 virtual-ip 192.168.20.254

[AR1-GigabitEthernet0/0/1.20] int g0/0/0

[AR1-GigabitEthernet0/0/0] ip address 100.1.10.1 24

AR2

[AR2] interface g0/0/1.10

[AR2-GigabitEthernet0/0/1.10] ip address 192.168.10.253 24

[AR2-GigabitEthernet0/0/1.10] dot1q termination vid 10

[AR2-GigabitEthernet0/0/1.10] arp broadcast enable

[AR2-GigabitEthernet0/0/1.10] vrrp vrid 10 virtual-ip 192.168.10.254

[AR2-GigabitEthernet0/0/1.10] interface g0/0/1.20

[AR2-GigabitEthernet0/0/1.20] ip address 192.168.20.253 24

[AR2-GigabitEthernet0/0/1.20] dot1q termination vid 20

[AR2-GigabitEthernet0/0/1.20] arp broadcast enable

[AR2-GigabitEthernet0/0/1.20] vrrp vrid 20 virtual-ip 192.168.20.254

[AR2-GigabitEthernet0/0/1.20] vrrp vrid 20 priority 200

[AR2-GigabitEthernet0/0/1.20] int g0/0/0

[AR2-GigabitEthernet0/0/0] ip address 100.1.20.1 24

配置 NAT 和静态路由

AR1

[AR1] ip route-static 0.0.0.0 0.0.0.0 100.1.10.3

[AR1] acl 2000

[AR1-acl-basic-2000] rule 5 permit source 192.168.10.0 0.0.0.255

[AR1-acl-basic-2000] rule 10 permit source 192.168.20.0 0.0.0.255

[AR1-acl-basic-2000] interface g0/0/0

[AR1-GigabitEthernet0/0/0] nat outbound 2000

AR2

[AR2] ip route-static 0.0.0.0 0.0.0.0 100.1.20.3

[AR2] acl 2000

[AR2-acl-basic-2000] rule 5 permit source 192.168.10.0 0.0.0.255

[AR2-acl-basic-2000] rule 10 permit source 192.168.20.0 0.0.0.255

[AR2-acl-basic-2000] interface g0/0/0                                                                                

[AR2-GigabitEthernet0/0/0] nat outbound 2000

AR3

[AR3] interface g0/0/0

[AR3-GigabitEthernet0/0/0] ip address 100.1.10.3 24

[AR3-GigabitEthernet0/0/0] int g0/0/1

[AR3-GigabitEthernet0/0/1] ip address 100.1.20.3 24

[AR3-GigabitEthernet0/0/1] interface lo 0

[AR3-LoopBack0] ip address 8.8.8.8 32

配置 BFD

AR1

[AR1] bfd

[AR1-bfd] quit

[AR1] bfd 1to3 bind peer-ip 100.1.10.3 source-ip 100.1.10.1 auto

AR3

[AR3] bfd

[AR3-bfd] quit

[AR3] bfd 3to1 bind peer-ip 100.1.10.1 source-ip 100.1.10.3 auto

配置 R1 的 VRRP 联动bfd 会话

AR1

[AR1] interface g0/0/1.10

[AR1-GigabitEthernet0/0/1.10]vrrp vrid 10 track bfd-session session-name

1to3 reduced 150

关闭交换机S2 g0/0/2口，观察流量情况