Cisco Track SLA NAT冗余配置

一、拓扑图

 

 

二、简单说明：

1. R1模拟企业出口路由器
2. R2作为ISP1网关
3. R3作为ISP2网关
4. R4 Loopback0模拟公网网站IP地址

三、实现功能：

1. 正常情况下LAN1出口为ISP1、LAN2出口为ISP2
2. 当其中一条ISP链路故障时自动切换至另一出口

四、设备配置

1. R1_GW配置如下:

ip sla monitor 1                                                    #配置SLA检测
 type echo protocol ipIcmpEcho 12.1.1.2 source-ipaddr 12.1.1.1      #检测类型为ICMP
 frequency 10                                                       #检测频率10S
ip sla monitor schedule 1 life forever start-time now               #创建SLA检测计划

ip sla monitor 2
 type echo protocol ipIcmpEcho 13.1.1.3 source-ipaddr 13.1.1.1
 frequency 10
ip sla monitor schedule 2 life forever start-time now         
!
track 1 rtr 1 reachability          #创建Track监测机制1并绑定SLA1
!
track 2 rtr 2 reachability          #创建Track监测机制2并绑定SLA2
! 
interface Ethernet0/0
 description TO_LAN1
 ip address 192.168.100.254 255.255.255.0
 ip nat inside
 ip policy route-map PBR          #调用PBR策略
!
interface Ethernet0/1
 description TO_LAN2
 ip address 192.168.200.254 255.255.255.0
 ip nat inside
 ip policy route-map PBR          #调用PBR策略
!
interface Ethernet0/2
 description TO_ISP1
 ip address 12.1.1.1 255.255.255.0
 ip nat outside
!
interface Ethernet0/3
 description TO_ISP2
 ip address 13.1.1.1 255.255.255.0
 ip nat outside
!
ip nat inside source route-map AAA interface Ethernet0/2 overload
ip nat inside source route-map BBB interface Ethernet0/3 overload
ip nat inside source route-map CCC interface Ethernet0/2 overload
ip nat inside source route-map DDD interface Ethernet0/3 overload
!
ip access-list extended LAN1
 permit ip 192.168.100.0 0.0.0.255 any
 permit ip any 192.168.100.0 0.0.0.255

ip access-list extended LAN2
 permit ip 192.168.200.0 0.0.0.255 any
 permit ip any 192.168.200.0 0.0.0.255
!
route-map PBR permit 10
 match ip address LAN1
 set ip next-hop verify-availability 12.1.1.2 1 track 1      #设置下一跳地址为12.1.1.2（如果track1失效则调用下方设置）
 set ip next-hop verify-availability 13.1.1.3 2 track 2
!
route-map PBR permit 20
 match ip address LAN2
 set ip next-hop verify-availability 13.1.1.3 1 track 2      #设置下一跳地址为12.1.1.2（如果track2失效则调用下方设置）
 set ip next-hop verify-availability 12.1.1.2 2 track 1
!         
route-map AAA permit 10                   #创建route-mapAAA
 match ip address LAN1                    #匹配列表LAN1
 match interface Ethernet0/2              #匹配出接口e0/2
!
route-map BBB permit 10
 match ip address LAN1
 match interface Ethernet0/3
!
route-map CCC permit 10
 match ip address LAN2
 match interface Ethernet0/2
!
route-map DDD permit 10
 match ip address LAN2
 match interface Ethernet0/3

　　2.　　R2配置

interface Ethernet0/0
 description ISP1_OUT
 ip address 12.1.1.2 255.255.255.0
 half-duplex
!
interface Ethernet0/1
 ip address 24.1.1.2 255.255.255.0
 half-duplex
!
interface Ethernet0/2
 no ip address
 shutdown
 half-duplex
!
interface Ethernet0/3
 no ip address
 shutdown
 half-duplex

ip route 10.1.1.0 255.255.255.0 24.1.1.4

　　3.　　R3配置

interface Ethernet0/0
 description ISP2_OUT
 ip address 13.1.1.3 255.255.255.0
 half-duplex
!
interface Ethernet0/1
 ip address 34.1.1.3 255.255.255.0
 half-duplex
!
interface Ethernet0/2
 no ip address
 shutdown
 half-duplex
!
interface Ethernet0/3
 no ip address
 shutdown
 half-duplex
!
ip route 10.1.1.0 255.255.255.0 34.1.1.4

　　4.　　R4配置

interface Loopback0
 ip address 10.1.1.1 255.255.255.0
!
interface Ethernet0/0
 no ip address
 shutdown
 half-duplex
!
interface Ethernet0/1
 ip address 24.1.1.4 255.255.255.0
 half-duplex
!
interface Ethernet0/2
 ip address 34.1.1.4 255.255.255.0
 half-duplex
!
interface Ethernet0/3
 no ip address
 shutdown
 half-duplex
!
ip route 12.1.1.0 255.255.255.0 24.1.1.2
ip route 13.1.1.0 255.255.255.0 34.1.1.3