Multiple IP SLA tracked routes

[William Benson]

I'm pretty sure this should work, but I hate assuming anything.  I have three gateways on my network:

1. 50Mb Ethernet connection to MPLS for VOIP, Data, and Internet (for example local gateway 10.1.1.1)

2. 20Mb Cable modem, failover high speed Internet (for example local gateway 10.1.1.2)

3. 1.5 T1 MPLS connection to partnered organization (data also available on this T1) (for example local gateway 10.1.1.3)

I have specific routes in place for traffic that must go over the Ethernet for VOIP and routes for data that must go through the T1 for data transfer between partnered Org.  We work on the Gulf Coast here (hurricane alley), and I'd like to try and build as much redundancy into the network as possible.  We've moved our business applications to an offsite data center with replicated data centers available incase the primary data center fails.  As long as we have an active internet connection the business system should be available to all staff via a web based thin client connection (Citrix).

I already have a track in place for the Ethernet cut to fail the default route over to the cable modem should it go down.  I would like to build another IP SLA track on cable modem and should it go down fail the default route over to the T1.

So my question in short is can you setup multiple tracked routes and fail over in order of preference based on administrative distance to that route.

Example:

ip route 0.0.0.0 0.0.0.0 10.1.1.1 track 1 1

ip route 0.0.0.0 0.0.0.0 10.1.1.2 track 10 10

ip route 0.0.0.0 0.0.0.0 10.1.1.3 20

Would this fail my default route from the Ethernet cut, to the cable mode, and then finally to the T1 as a last resort?  I think it should but I've never tried to setup multiple routes with IP SLA tracks like this so a little confirmation would be appreciated.

Thanks!

[John Blakley · Accepted solution]

I don't see a problem with this. It should work fine. Your 10.1.1.1 would be in the routing table first, and then if it went down, it would fail over to the 10.1.1.2 with an AD of 10. If your original came back up, it would be put back in. Let's say that 10.1.1.2 went down and 10.1.1.1 was up. If 10.1.1.1 went down, your 10.1.1.3 would be put into the routing table until one of the others recovered.

HTH,

John

[William Benson]

That's the way I thought it should work.  I tried googling for confirmation that you could setup multiple IP SLA routes, but Google was coming up empty.  I kept seeing individual failovers but nothing on setting up for failover routes like this for 3+ ISPs.  I just wanted a little confirmation that you could setup multiple tracks like this and assign AD to them so they failover in a specified list of priority.

Thanks for the feedback John!