Cisco IP SLA+EEM 检测MSTP线路加快路由收敛
这个方法需要enterprise的ios .ip base是不支持这些特性的
众所周知，MSTP线路如果在中间某一点出现故障，是不会导致设备物理端口出现协议层down的。物理接口处于UP状态时，路由是不会进行收敛的。为了避免此种情况，并加快网络收敛速度，思科工程师建议使用IP SLA+EEM。于是使用两台Cisco2801进行模拟测试，使用的IOS为c2801-entbasek9-mz.150-1.M.bin。
模拟拓扑如下：
设备的主要配置如下： R1: hostname R1 !
boot-start-marker boot-end-marker !
enable secret 5 $1$HYYK$evVsS7tjNc5JkX/VuIhCE0 !
no aaa new-model
no network-clock-participate wic 1 dot11 syslog
ip source-route ! ! ! ! ip cef
no ip domain lookup
multilink bundle-name authenticated ! ! ! ! ! archive log config hidekeys ! !
controller E1 0/1/0 line-termination 75-ohm channel-group 0 unframed !
!
track 1 ip sla 1 ! ! ! !
interface Loopback0
ip address 56.16.0.1 255.255.255.0 !
interface Loopback1
ip address 56.16.128.1 255.255.255.0 !
interface FastEthernet0/0
ip address 56.16.234.1 255.255.255.252 speed 100 full-duplex !
interface FastEthernet0/1 speed 100 full-duplex !
interface Serial0/1/0:0
ip address 56.16.244.1 255.255.255.252 !
router rip version 2
offset-list 0 in 3 Serial0/1/0:0 offset-list 0 out 3 Serial0/1/0:0 network 56.0.0.0 no auto-summary !
ip forward-protocol nd ! !
ip http server
no ip http secure-server
ip route 56.16.234.2 255.255.255.255 FastEthernet0/0 ! ip sla 1
icmp-echo 56.16.234.2 frequency 5
ip sla schedule 1 life forever start-time now disable-eadi !
tftp-server flash:c2801-entbasek9-mz.150-1.M.bin !
control-plane ! !
line con 0 line aux 0 line vty 0 4 password cisco login !
scheduler allocate 20000 1000 event manager environment 1 event manager applet rip_track_1 event track 1 state down action 1.0 cli command \action 2.0 cli command \action 3.0 cli command \
action 3.1 cli command \物理端口后，路由表就会发生变化，原本从F0/0学到的路由删除，取而代之的是从S0/1/0：0学到的路由
action 3.2 cli command \执行no shut命令是为了避