IPSLA to Track Multiple Objects

IPSLA is a very handy feature but one specific use case for it is determining if a connection is up, for example a connection to the Internet. A router can use IPSLA to continuously ping a resource on the Internet (for example Google.com) and if they resource becomes unreachable then the router can act upon this. This is especially useful if your Internet connection is not physically down but it has no connectivity, perhaps there is issues within the service provider but because the interface is not down features like HSRP tracking will not kick in.

One draw back with this is that if the resource on the Internet goes down then the router thinks the connection has gone down and will act upon this. To stop this happening Enhanced Object Tracking can be used with IPSLA so that 2 (or more) objects can be tracked, with a Boolean expression, I.E. Google.com and cisco.com with the AND boolean expression would mean both objects would have to unreachable in order for the router to act, and this is highly unlikely, unless your Internet connection is down.