Cisco Enhanced Object Tracking

HSRP中可以对上联口的UP/Down状态进行监控，从而实现冗余网关的切换

EOT可以对接口提供更丰富的监控：

• IP routing是否enable（例如ip routing被全局关闭）

• 端口UP/Down

• 接口是否被分配IP（上联口IP为DHCP分配）

  
  

监控上行端口UP/DOWN

监控某条路由是否可达

正常情况下

SW1#show track
Track 5
 IP route 2.2.2.2 255.255.255.255 reachability
 Reachability is Up (OSPF)
   3 changes, last change 00:01:06
 First-hop interface is FastEthernet1/5
 Tracked by:
   HSRP Vlan100 100

而当2.2.2.2路由失效时

Track 5
 IP route 2.2.2.2 255.255.255.255 reachability
 Reachability is Down (no route)
   2 changes, last change 00:12:26
 First-hop interface is unknown
 Tracked by:
   HSRP Vlan100 100

引发HSRP Active切换

SW1#
*Mar  1 00:23:02.647: %HSRP-5-STATECHANGE: Vlan100 Grp 100 state Active -> Speak
*Mar  1 00:23:12.647: %HSRP-5-STATECHANGE: Vlan100 Grp 100 state Speak -> Standby