Alienrealms

IP SLA Failover

How to use a secondary Internet connection as a backup with automated failover.

Set your routes, the primary route is the one that is “tracked”, the secondary one has the highest metric

route outside 0.0.0.0 0.0.0.0 195.59.154.93 1  track 1
route backup 0.0.0.0 0.0.0.0 213.14.25.33 254

Set the tracking

track 1 rtr 1 reachability
sla monitor 1
type echo protocol ipIcmpEcho 213.38.254.169 interface outside
num-packets 3
frequency 10
sla monitor schedule 1 life forever start-time now

When choosing a host to use I tend to use a router one hop upstream of the local  gateway device. It’s also probably worth pinging the device while you are creating the config so that you know that it’s not going to start dropping ICMP requests after a couple of minutes and it fails over unnecessarily!