什么是浮动路由
浮动路由又称为路由备份
两条或多条链路组成浮动路由
相同的目的地址，不同的下一跳地址，另一条下一跳的优先级低
VRRP简介
虚拟路由器冗余协议（VRRP）是一种选择协议，它可以把一个虚拟路由器的责任动态分配到局域网上的VRRP路由器中的一台。控制虚拟路由器IP地址的VRRP路由器称为主路由器，它负责转发数据包到这些虚拟IP地址。一旦主路由器不可用，这种选择过程就提供了动态的故障转移机制，这就允许虚拟路由器的IP地址可以作为终端主机的默认第一跳路由器。使用VRRP的好处是有更高的默认路径的可用性而无需在每个终端主机上配置动态路由或路由发现协议。使用VRRP ，可以通过手动或DHCP设定一个虚拟IP地址作为默认路由器。虚拟 IP 地址在路由器间共享，其中一个指定为主路由器而其它的则为备份路由器
实验环境搭建
PC机配置
PC2配置同PC1，记得点击应用哦
sw1配置
[rsw1]v b 10 20 100
[rsw1]int g0/0/2
[rsw1-GigabitEthernet0/0/2]p l t
[rsw1-GigabitEthernet0/0/2]p t a v a
[rsw1-GigabitEthernet0/0/2]un sh
[rsw1-GigabitEthernet0/0/2]q
[rsw1]int Vlanif 10
[rsw1-Vlanif10]ip add 192.168.10.10 24
[rsw1-Vlanif10]un sh
[rsw1-Vlanif10]int vlanif 20
[rsw1-Vlanif20]ip add 192.168.20.10 24
[rsw1-Vlanif20]un sh
[rsw1-Vlanif20]int vlanif 100
[rsw1-Vlanif100]ip add 11.0.0.2 30
[rsw1-Vlanif100]un sh
[rsw1-Vlanif100]q
[rsw1]int g0/0/1
[rsw1-GigabitEthernet0/0/1]p l a
[rsw1-GigabitEthernet0/0/1]p d v 100
[rsw1-GigabitEthernet0/0/1]un sh
[rsw1-GigabitEthernet0/0/1]q
[rsw1]ip route-static 0.0.0.0 0.0.0.0 11.0.0.1
[rsw1]q
[rsw1]int Vlanif 10
[rsw1-Vlanif10]vrrp vrid 1 virtual-ip 192.168.10.1 设置虚拟IP地址
[rsw1-Vlanif10]vrrp vrid 1 priority 120 设置优先级
[rsw1-Vlanif10]vrrp vrid 1 track int g0/0/1 设置监听
[rsw1-Vlanif10]vrrp vrid 1 track int g0/0/2
[rsw1-Vlanif10]int vlanif 20
[rsw1-Vlanif20]vrrp vrid 2 virtual-ip 192.168.20.1 这是备用不用设置监听
[rsw1-Vlanif20]vrrp vrid 2 priority 115
[rsw1-Vlanif20]
[rsw1-Vlanif20]q
sw2配置
[rsw2]v b 10 20 100
[rsw2]int g0/0/2
[rsw2-GigabitEthernet0/0/2]p l t
[rsw2-GigabitEthernet0/0/2]p t a v a
[rsw2-GigabitEthernet0/0/2]un sh
[rsw2-GigabitEthernet0/0/2]int g0/0/1
[rsw2-GigabitEthernet0/0/1]p l a
[rsw2-GigabitEthernet0/0/1]p d v 100
[rsw2-GigabitEthernet0/0/1]un sh
[rsw2-GigabitEthernet0/0/1]q
[rsw2]int Vlanif 10
[rsw2-Vlanif10]ip add 192.168.10.20 24
[rsw2-Vlanif10]un sh
[rsw2-Vlanif10]int vlanif 20
[rsw2-Vlanif20]ip add 192.168.20.20 24
[rsw2-Vlanif20]un sh
[rsw2-Vlanif20]int vlanif 100
[rsw2-Vlanif100]ip add 12.0.0.2 30
[rsw2-Vlanif100]un sh
[rsw2-Vlanif100]q
[rsw2]ip route-static 0.0.0.0 0.0.0.0 12.0.0.1
[rsw2]int Vlanif 10
[rsw2-Vlanif10]vrrp vrid 1 virtual-ip 192.168.10.1
[rsw2-Vlanif10]vrrp vrid 1 priority 115
[rsw2-Vlanif10]int vlanif 20
[rsw2-Vlanif20]vrrp vrid 2 virtual-ip 192.168.20.1 设置虚拟IP
[rsw2-Vlanif20]vrrp vrid 2 priority 120 设置优先级
[rsw2-Vlanif20]vrrp vrid 2 track int g0/0/1 设置监听
[rsw2-Vlanif20]vrrp vrid 2 track int g0/0/2
[rsw2-Vlanif20]q
sw3配置
[sw3]v b 10 20
[sw3]int e0/0/1
[sw3-Ethernet0/0/1]p l a
[sw3-Ethernet0/0/1]p d v 10
[sw3-Ethernet0/0/1]un sh
[sw3-Ethernet0/0/1]int e0/0/2
[sw3-Ethernet0/0/2]p l a
[sw3-Ethernet0/0/2]p d v 20
[sw3-Ethernet0/0/2]un sh
[sw3-Ethernet0/0/2]int g0/0/1
[sw3-GigabitEthernet0/0/1]p l t
[sw3-GigabitEthernet0/0/1]p t a v a
[sw3-GigabitEthernet0/0/1]un sh
[sw3-GigabitEthernet0/0/1]int g0/0/2
[sw3-GigabitEthernet0/0/2]p l t
[sw3-GigabitEthernet0/0/2]p t a v a
[sw3-GigabitEthernet0/0/2]un sh
r1配置
[r1]int g0/0/0
[r1-GigabitEthernet0/0/0]ip add 11.0.0.1 30
[r1-GigabitEthernet0/0/0]un sh
[r1-GigabitEthernet0/0/0]int g0/0/1
[r1-GigabitEthernet0/0/1]ip add 12.0.0.1 30
[r1-GigabitEthernet0/0/1]un sh
[r1-GigabitEthernet0/0/1]int loo 0
[r1-LoopBack0]ip add 1.1.1.1 24
[r1-LoopBack0]q
[r1]ip route-static 192.168.10.0 24 11.0.0.2
[r1]ip route-static 192.168.10.0 24 12.0.0.2 preference 70
[r1]ip route-static 192.168.20.0 24 12.0.0.2
[r1]ip route-static 192.168.20.0 24 11.0.0.2 preference 70
实验校验
首先在pc1里面ping1.1.1.1
在sw2上面进入g0/0/1 关闭这个接口
[rsw2]int g0/0/1
[rsw2-GigabitEthernet0/0/1]shutdown
然后再次ping1.1.1.1
SO FINE