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Floating Static Route Issue

brianschaefer
Level 1
Level 1

I have 7 sites running EIGRP and one primary internet/wan connection. One of our buildings has an issue where they loose connectivity a couple of times a month (another issue entirely).  We put a cable modem backup for a couple of vlans that need the internet to complete daily operations. I setup a floating static route with an AD of 250 for the cable modem backup link. Last night they lost internet for a few minutes, then it came back. The floating static route worked, but never went back to the primary internet connection.  Is this normal? do I have to manually clear all the routes and let EIGRP reconverge? or is there a better way to accomplish this?

18 Replies 18

sorry.... I edited my last post.

to answer your question;  the floating static is configured on the router with the cable modem and is then advertised to the head end

brianschaefer wrote:

sorry.... I edited my last post.

to answer your question;  the floating static is configured on the router with the cable modem and is then advertised to the head end

Brian

It is as we have been saying i think. There are 2 AD 170 default-routes. One from your ISP and one from your cable modem device. When the ISP goes down the floating static is used on cable modem and redistributed to head end. When ISP comes back up the headend receives the default-route from ISP and this is also AD 170 but the metric to the cable modem is better so that one remains on the head end router.

So either modify the metric (delay) on the headend to cable modem connection so the metric is better for the ISP connection or as Rick suggests use an offset-list in on then headend router for the routes received on the interface connected to the cable modem router.

Either should work.

Jon

I think you nailed it.

last question before I mark your reply correct. can I put the delay on the interface for the cable modem at the dark fiber site?

Brian

No, delay is outgoing so the headend router would be where you needed to configure it. If this is a problem then an offset-list as mentioned by Rick is an equally good solution.

Either way you are simply making sure that if both routes are available to the headend router the better metric is via the ISP link.

Jon

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