how do i configure a cisco 4948 switch to have a primary and secondary internet connection?

[andrewpaulsen]

I'm currently trying to configure a catalyst 4948 switch that has 2 internet connections one primary and one secondary. the primary is a fiber connection and the secondary is a wireless connection. i have looked at Link State Tracking but not sure if this is what i need to use in order to get the results i want. which are if the fiber for some reason goes down i want the wireless to kick in automatically as the internet connection until the fiber is fixed.

[Jon Marshall · Accepted solution]

Andrew

The usual way is to have two default routes but configure the one pointing to the wireless with a higher AD so it is not installed into the routing table unless the primary link goes down.

Normally if your physical link goes via a switch you need to track the current default route via the primary link because if the other end goes down your end doesn't know because it's connection to the switch is still up so it keeps the current default route.

In addition tracking allows you detect a failure beyond the next hop IP so if there is a failure further upstream you can also failover.

Can you confirm whether your link from the 4948 is a direct link to the next hop ie. no intermediate switch, in which case if the 4948 is a routed port you may not need to track ie. if the next goes down does your interface on the 4948 go down as well.

If so you may be able to just use the two default routes as suggested.

If not you need tracking which i believe your switch supports but it depends on the IOS version and the feature set you have running.

Jon

[andrewpaulsen]

Thanks Jon

in the scenario this is a Fiber connection that connects 4 major city entities together and all work on one network with cisco 4948 switches at each hop along the network in which we supply the fiber connection and the wireless connection also each location has a ASA5505 as the router/firewall so that may be the route i have to go.