Резервирование L2

Link tracking

Switch(config)#link state track 1
Switch(config)#int fa 0/1
Switch(config-if)#link state group 1 upstream
Switch(config-if)#int fa 0/4
Switch(config-if)#link state group 1 downstream

Switch(config)#int fa 0/25
Switch(config-if)#channel-group 4 mode active
Switch(config-if)#int fa 0/26
Switch(config-if)#channel-group 4 mode active

Просмотр состояния агрегированного канала номер 2

Switch#sh etherchannel  
Switch#sh int po2

Fate Sharing

The underlying assumption is simple: if the routing protocol manages to exchange information between adjacent nodes, there won’t be any problems with the user traffic. Furthermore, if the routing protocol updates in a distance vector protocol made it from egress router to ingress router, the traffic should experience no problems when being sent in the reverse direction. http://blog.ipspace.net/2014/08/fate-sharing-in-ip-networks.html