Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Backup link (route) for redundancy help?

Hey all.  We had a complete outage the other day, a heavy equipment pience of machinary crushed our ISPs entire fiber, took out pretty much everything in the area, including a cell phone tower.

I've been asked to setup a redundant backup link just in case this happens again.  I have a Satellite service being installed shortly (we pretty much have only one ISP up this far north).

This service will be used by 2 companies, one we manage their router and the other we do not.  Right now the one that we manage just routes out our 6509s and out to the internet.  The other company have their own router but plug into our internet switch and out.

So I'm looking for ways to make this fail over to the backup link automatically. I have a few different routers here and a few ASAs I can use.  Reading up on this I'm thinking one of the only ways I can get this to work is to use tracking and IP SLA commands?  If this is the case I would have to get them to do the same on their router.

For the company we manage I was thinking I would leave them plugged into a layer 3 switch, routed to the 6509 and also have them routed to another router in front of the Satellite service.  I was going to use a delay command but I think it would only use the other if the actual link went down which won't work in this case.

I will work with the other company later, we will figure it out but I want to test out now I can get this going with what we manage here.  Sorry if this is confusing or not detailed enough, any help would be greatly appreciated.



Everyone's tags (4)
New Member

Backup link (route) for redundancy help?

In the exact failure that you had your solution is very simple. for your default route ( for ex. 1) the last 1 being your AD for your static default route. so for your backup route  you just can increase the metric or AD for example your floating static route to your sattelite ( 3). Keep in mind this will only work if your fiber is smashed ( interface/link goes down).  Also, this is different than an SLA because you are not testing your upstream connectivity just yout PTP connectivity. Please rate answers.



New Member

Backup link (route) for redundancy help?

I think I need to use SLA for that reason though.  You see I don't want to put this second route on our 6509 as we have 3000 users off of that device (much like a hotel).  I only want a certain number of users to be able to access that backup link, business users.  Right now I have them on their own layer 3 switch.  So my thought was that I would introduce a new router, my default route would be to the 6509 (internet, dhcp, etc) and then have another route to the other router connected to the other service.  If the internet service attached to the 6509 went down it would then fail over to the other service.  I'm hoping there is an easier way but I can't think of it.


CreatePlease login to create content