Multilayer S
cisco VRRP(TRACK+SLA) 配置实例
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一.实验目的
Cisco vrrp 配置实例(本例主要测试 cisco track+sla 机制)
注:本实验全部由 gns3 模拟所有设备
二.实验拓扑
三.具体操作
1. 基本配置
相关设备的地址及连通配置,如上图所示各设备节点地址已经标注,此处配置
部分省略!
2. VRRP 基本配置
1) vrrp 原理
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
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Multilayer S
cisco VRRP(TRACK+SLA) 配置实例
置动态路由或路由发现协议。 VRRP 包封装在 IP 包中发送。
2) vrrp 在此例中的基本配置
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R4
R5
R4(config)#int f 0/1
R4(config-if)#vrrp 1 ip 192.168.2.1
R4(config-if)#vrrp 1 priority 200
R4(config-if)#vrrp 1 preempt
R5(config)#int f 0/1
R5(config-if)#vrrp 1 ip 192.168.2.1
R5(config-if)#vrrp 1 priority 110
R5(config-if)#vrrp 1 preempt
3) vrrp 基本测试
R4#show vrrp
FastEthernet0/1 - Group 1
State is Master
Virtual IP address is 192.168.2.1
Virtual MAC address is 0000.5e00.0101
Advertisement interval is 1.000 sec
Preemption enabled
Priority is 255 (cfgd 200)
Master Router is 192.168.2.1 (local), priority is 255
Master Advertisement interval is 1.000 sec
Master Down interval is 3.003 sec
R4#
R5#show vrrp
FastEthernet0/1 - Group 1
State is Backup
Virtual IP address is 192.168.2.1
Virtual MAC address is 0000.5e00.0101
Advertisement interval is 1.000 sec
Preemption enabled
Priority is 110
Master Router is 192.168.2.1, priority is 255
Master Advertisement interval is 1.000 sec
Master Down interval is 3.570 sec (expires in 3.178 sec)
R5#
3. vrrp 的功能测试
第一种情况:当拓扑中 R4 的 f0/1 口 down 时,(如下图)我们测试 vrrp 的
功能
R5#show vrrp
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Multilayer S
cisco VRRP(TRACK+SLA) 配置实例
QQ:1779737860
FastEthernet0/1 - Group 1
State is Master
Virtual IP address is 192.168.2.1
Virtual MAC address is 0000.5e00.0101
Advertisement interval is 1.000 sec
Preemption enabled
Priority is 110
Master Router is 192.168.2.2 (local), priority is 110
Master Advertisement interval is 1.000 sec
Master Down interval is 3.570 sec
R5#
PC1#traceroute 1.1.1.1
Type escape sequence to abort.
Tracing the route to 1.1.1.1
1 192.168.2.2 68 msec 40 msec 36 msec
2 56.1.1.2 116 msec * 100 msec
PC1#
注:vrrp 组将原来的备用口(r5 的 f0/1 切换到 master
状态,数据从 r5 这条链路上来!)
第二种情况:当拓扑中,R4 的 f0/0 口 down 时,(如下图)我们测试 vrrp
的功能
R4#show vrrp
FastEthernet0/1 - Group 1
State is Master
Virtual IP address is 192.168.2.1
Virtual MAC address is 0000.5e00.0101
Advertisement interval is 1.000 sec
Preemption enabled
Priority is 255 (cfgd 120)
Master Router is 192.168.2.1 (local), priority is 255
Master Advertisement interval is 1.000 sec
Master Down interval is 3.003 sec
R4#
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Multilayer S
cisco VRRP(TRACK+SLA) 配置实例
PC1#ping 1.1.1.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:
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U.U.U
Success rate is 0 percent (0/5)
PC1#tracer
PC1#traceroute 1.1.1.1
Type escape sequence to abort.
Tracing the route to 1.1.1.1
1 192.168.2.1 36 msec 60 msec 20 msec
2 192.168.2.1 !H * !H
PC1#
注:此时 R4 的 f0/1 口仍然充当 Master 角色,数据依然
决定从 R4 这条链路上来,然而此时的出口 f0/0 处于
down 状态,数据从 f0/1 口上来后无法进行正常转发!
对于这种情况的解决方法是:
相关命令
R4(config-if)#ip add 192.168.2.3 255.255.255.0
在 R4 的 vrrp 组下,启用 track 端口机制,即当发现 R4 的出口(f0/0)
出现 down 状态时,通过降低本端设备 vrrp 优先级的方式来达到备用 vrrp
服务器切换到 MASTER 状态,从而保证数据正常传输的方法!具体操作如
下:
R5
更改 f0/1 地址
定义 track 语句
应用 track
注:可能有人对于更改 f0/1 口地址这步比较迷惑,原因是这样的:如果 vrrp
要做 track 就不能将让虚拟路由器的 ip 地址和真实路由器的 IP 地址相同
如果使用真实路由器的 IP 地址作为虚拟路由 IP 地址的话,优先级将会被固
定为 255,不能通过 track 来 object 来减少
R4#show vrrp
R4(config)#track 1 interface fastEthernet 0/0 line-protocol
R4(config-if)#vrrp 1 track 1 decrement 90
FastEthernet0/1 - Group 1
State is Backup
Virtual IP address is 192.168.2.1
Virtual MAC address is 0000.5e00.0101
Advertisement interval is 1.000 sec
Preemption enabled
Priority is 30 (cfgd 120)
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Multilayer S
cisco VRRP(TRACK+SLA) 配置实例
QQ:1779737860
Track object 1 state Down decrement 90
Master Router is 192.168.2.2, priority is 110
Master Advertisement interval is 1.000 sec
Master Down interval is 3.531 sec (expires in 3.219 sec)
R4#
R5#show vrrp
FastEthernet0/1 - Group 1
State is Master
Virtual IP address is 192.168.2.1
Virtual MAC address is 0000.5e00.0101
Advertisement interval is 1.000 sec
Preemption enabled
Priority is 110
Master Router is 192.168.2.2 (local), priority is 110
Master Advertisement interval is 1.000 sec
Master Down interval is 3.570 sec
R5#
PC1#ping 1.1.1.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 52/64/76 ms
PC1#
第三种情况:当拓扑中,R6 的 f0/0 口 down 时,(如下图)
我们测试 vrrp 的功能
R4#show vrrp
FastEthernet0/1 - Group 1
State is Master
Virtual IP address is 192.168.2.1
Virtual MAC address is 0000.5e00.0101
Advertisement interval is 1.000 sec
Preemption enabled
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Multilayer S
cisco VRRP(TRACK+SLA) 配置实例
QQ:1779737860
Priority is 120
Track object 1 state Up decrement 90
Master Router is 192.168.2.3 (local), priority is 120
Master Advertisement interval is 1.000 sec
Master Down interval is 3.531 sec
R4#
注:此时由于 r4 的出口 f0/0 处于 up 状态,数据从 r4 上
来后由 f0/0 口出去,由于下一跳链路故障导致,数据依
然无法正常传输!
对于这种情况的解决方法是:要求 vrrp 在运行中具有检测吓一跳地址
状态的机制,即 track+sla,具体操作如下:
R4
Sla 相关
相关命令
R4(config)#ip sla 11
R4(config-ip-sla)#icmp-echo 46.1.1.2
R4(config)#icmp-echo 46.1.1.2 source-interface FastEthernet0/1
R4(config)# ip sla schedule 11 life forever start-time now
Track 相关
vrrp 应用
R4(config-if)#
R4(config)#track 11 rtr 11 reachability
R4(config-if)#vrrp 1 track 11 decrement 50
*Mar 1 04:31:59.222: %VRRP-6-STATECHANGE: Fa0/1 Grp 1 state Master ->
Backup
R4(config-if)#
R4#show vrrp
FastEthernet0/1 - Group 1
State is Backup
Virtual IP address is 192.168.2.1
Virtual MAC address is 0000.5e00.0101
Advertisement interval is 1.000 sec
Preemption enabled
Priority is 70 (cfgd 120)
Track object 11 state Down decrement 50
Master Router is 192.168.2.2, priority is 110
Master Advertisement interval is 1.000 sec
Master Down interval is 3.531 sec (expires in 2.683 sec)
R4#
注:此种情况对于解决 r4 的 f0/0 端口 down 或是 r6 的 f0/0 口 down 都启作用,
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Multilayer S
cisco VRRP(TRACK+SLA) 配置实例
QQ:1779737860
是使用 vrrp 及 hsrp 的必备配置!
路由器 R4 配置存根
4.
R4#show run
Building configuration...
Current configuration : 1050 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname R4
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
memory-size iomem 5
!
!
ip cef
no ip domain lookup
!
!
ip auth-proxy max-nodata-conns 3
ip admission max-nodata-conns 3
!
multilink bundle-name authenticated
!
!
!
!
!
!
!
!
!
!
!
!
!
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Multilayer S
cisco VRRP(TRACK+SLA) 配置实例
QQ:1779737860
!
archive
log config
hidekeys
!
!
!
!
!
track 11 rtr 11 reachability
!
!
!
!
interface FastEthernet0/0
ip address 46.1.1.1 255.255.255.0
duplex auto
speed auto
!
interface FastEthernet0/1
ip address 192.168.2.3 255.255.255.0
duplex auto
speed auto
vrrp 1 ip 192.168.2.1
vrrp 1 priority 120
vrrp 1 track 11 decrement 50
!
no ip http server
no ip http secure-server
!
ip forward-protocol nd
ip route 0.0.0.0 0.0.0.0 46.1.1.2
!
!
ip sla 11
icmp-echo 46.1.1.2 source-interface FastEthernet0/1
ip sla schedule 11 life forever start-time now
!
!
!
!
control-plane
!
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