I've 2x877 routers which are each connected to a separate ADSL circuit with different providers for redundancy.
Currently I have HSRP setup for failover should one of the devices die. This doesn't cover failover should the upstream ADSL circuit stop working (leaving line protocol up, but no routing of traffic). And it means 1 ADSL circuit is left not doing much as all traffic goes out the primary Router.
I would like to start using both routers/circuits, with load balancing and failover.
What i've thought is, if I configure each router to track a couple of hosts on the internet (our vpn host at another site, and perhaps http://www.google.com), and then use the reachability of those hosts as an indicator of whether the circuit connected to that router is up, i can then use that status to trigger a fail over and route all traffic out via the other circuit.
While both circuits are active and working i would like to be able to load balance traffic in and out of both ADSL circuits, but am not sure what type of load balancing i should use (i presume GLBP is the best option). I understand that if the circuit fails that a persistant session (like RDP or SSH) is using fails, then it will have to be re-established to initiate the session out the other router.
Currently everything i've looked at seems to rely on decrementing and if ADSL_1 circuit fails more often than ADSL_2 then it's object weighting or priority will be decremented more often and thus, much lower than ADSL_2 so no fail over will occur unless ADSL_2 fails the same number of times to bring it's weighting/priority to below ADSL_1 (i hope i make sense).
I want to fail based on state of a tracked object, ie if tracked_object_1 is UP all is well and load balance between 2 circuits but when tracked_object_1 is DOWN route via the other circuit, and when tracked_object_1 comes back UP, load balance again.
Any help would be much appreciated, as i'm fairly new to the track command and GLBP on the 877.