HSRP与链路追踪

1、链路追踪的概念：
当网络中存在着HSRP的备份路由器时，可以配置HSRP的上行链路追踪，当指定的追踪接口down掉时，马上减小该HSRP设备的优先级，使另一个备份设备能马上被激活成为ACTIVE状态，并接替down掉的设备继续引导路由数据，实现网络的畅通性

2、拓扑规划：




3、案例实施：
1）、各设备配置：
R1配置：

interface Loopback0
ipaddress 202.102.12.1 255.255.255.0
interface Serial1/0
ipaddress 172.16.0.1 255.255.255.252
serial restart-delay 0
clock rate 64000
!
interface Serial1/1
ipaddress 172.16.0.5 255.255.255.252
serial restart-delay 0
clock rate 64000

R2配置：

interface FastEthernet0/0.10
encapsulation dot1Q 10
ipaddress 192.168.10.1 255.255.255.0
ipnat inside
ipvirtual-reassembly
standby 10 ip 192.168.10.254
standby 10 priority 120
standby 10 preempt
standby 10 track Serial1/0 30
!
interface FastEthernet0/0.20
encapsulation dot1Q 20
ipaddress 192.168.20.1 255.255.255.0
ipnat inside
ipvirtual-reassembly
standby 20 ip 192.168.20.254
standby 20 preempt

interface Serial1/0
ipaddress 172.16.0.2 255.255.255.252
ipnat outside
ipvirtual-reassembly
serial restart-delay 0

ip route 0.0.0.0 0.0.0.0 Serial1/0
ip nat inside source list 100 interfaceSerial1/0 overload

R3配置：

interface FastEthernet0/0.10
encapsulation dot1Q 10
ipaddress 192.168.10.2 255.255.255.0
ipnat inside
ipvirtual-reassembly
standby 10 ip 192.168.10.254
standby10 preempt
!
interface FastEthernet0/0.20
encapsulation dot1Q 20
ipaddress 192.168.20.2 255.255.255.0
ipnat inside
ipvirtual-reassembly
standby 20 ip 192.168.20.254
standby 20 priority 120
standby 20 preempt
standby 20 track Serial1/1 30

interface Serial1/1
ipaddress 172.16.0.5 255.255.255.252
ipnat outside
ipvirtual-reassembly
serial restart-delay 0

ip route 0.0.0.0 0.0.0.0 Serial1/1
ip nat inside source list 100 interfaceSerial1/1 overload

Sw1配置：

interface FastEthernet0/0
switchport mode trunk
!
interface FastEthernet0/1
switchport mode trunk
!
interface FastEthernet0/2
switchport mode trunk
!
interface FastEthernet0/3
switchport access vlan 10
!
interface FastEthernet0/4
switchport access vlan 20

vlan database
vlan10
vlan20

Sw2配置：

interface FastEthernet0/0
switchport mode trunk
!
interface FastEthernet0/1
switchport mode trunk
!
interface FastEthernet0/2
switchport mode trunk
!
interface FastEthernet0/3
switchport access vlan 10
!
interface FastEthernet0/4
switchport access vlan 20

vlan database
vlan10
vlan20

PC1配置：

no ip routing

interface FastEthernet0/0
ipaddress 192.168.10.100 255.255.255.0
noip route-cache
duplex auto
speed auto

ip default-gateway 192.168.10.254

PC2配置：

no ip routing

interface FastEthernet0/0
ipaddress 192.168.20.100 255.255.255.0
noip route-cache
duplex auto
speed auto

ip default-gateway 192.168.20.254

PC3配置：

no ip routing

interface FastEthernet0/0
ipaddress 192.168.10.200 255.255.255.0
noip route-cache
duplexauto
speed auto

ip default-gateway 192.168.10.254

PC4配置：

no ip routing

interface FastEthernet0/0
ipaddress 192.168.20.200 255.255.255.0
noip route-cache

ip default-gateway 192.168.20.254

2）、配置完成后查看R2和R3的HSRP信息：
R2：




R3：




此时在PC2上跟踪一下到202.102.12.1的路由情况



在PC3上跟踪到202.102.12.1的路有情况



此时将R1的接口S1/0设置为shutdown模式，再查看HSRP信息：
R2：




R3：




此时再在PC1和PC2上跟踪到202.102.12.1的路由，发现R3自动接管原先的路由：
PC1：



PC3：




本文出自 “却邪水心泮” 博客，请务必保留此出处http://shmilyfl.blog.51cto.com/8897986/1680352