I have a lab setup simulating 2 routers connected to 2 different service providers. I am forcing all traffic to go through router1 using weight values.
I am simulating link failures by pulling the WAN connection on router1. The routing changes over quickly to router2. Doing a continuous ping from a windows box, the icmp echo only times out once.
When simulating a LAN link failure on router 1(pull the Ethernet cable), routing does not change over to router 2 until the BGP hold timers expire, which is 180 seconds.
Why does the LAN link failure take longer than the WAN? I can change the timers between the LAN peer group to speed this up, but I don't understand why I don't see the same results on the WAN failure.
The reason why the LAN failure takes time is it needs to wait for the dead interval time 180secs to detect it. If LAN is connected to a switch if its directly connected to a router the time will be different.