IP SLA Fail back question

ngthen · ‎07-09-2009

If my ISP were to go offline and the route that I am tracking is removed, is there a way to set a time before it can return to the main line? I know I could simply pull the cable if the line goes down but I am wondering if there is a way to automate it. For example ISP 1 goes down and ISP 2 takes over. Can I say that ISP 1 must be back up for 1 hour before switching back?

johnspaulding · ‎07-09-2009

Yes,

After you create you IP SLA instance you create you track rtr's

under the following

track 1 rtr 1

delay down (seconds) up (seconds)

this should be the value you are looking for.

xcz504d1114 · ‎07-09-2009

What method are you using to track? And are you running any routing protocols? BGP can suppress a route for a specified time period if it goes down then back up.

With object tracking, I believe the maximum abmount of delay you can introduce is 180 seconds.

HTH,

Craig

ngthen · ‎07-09-2009

I am not using any routing protocols and I am using icmp-echo for tracking. I have 2 ISPs and one is pretty much just on standby unless the main goes down. For example

ip sla 1

icmp-echo 4.2.2.2

frequency 3

ip sla schedule 1 start-time now life forever

track 1 rtr 1 reachability

ip route 0.0.0.0 0.0.0.0 1.1.1.1 track 1

ip route 0.0.0.0 0.0.0.0 1.1.1.2 20

So I guess the question is with this config, is there a way to prevent the main from coming back online for a period of time?

xcz504d1114 · ‎07-09-2009

The other poster had the right answer for you:

track 1 rtr 1 reachability

delay down

But it only has a limit of 180 seconds.

HTH,

Craig

johnspaulding · ‎07-09-2009

Yes,

as previously posted

Taking your example

ip sla 1

icmp-echo 4.2.2.2

frequency 3

ip sla schedule 1 start-time now life forever

track 1 rtr 1 reachability

delay down (seconds) up (seconds)

As mentions only up to 180 seconds