RIP, OSPF and adding static route

[richmorrow624]

I have sort of two questions really,

Here is the scenario:

We have RIP and OSPF running on a router at the HQ site. The router's ethernet is connected to 4503 switches and etherchanneled.

The switch is running rip and there is mutual redistribution of dynamic and static routes between the router and switch.

All of this is ddistributed to 8 remote sites.

The switches connect the HQ site to the Internet and the router directs traffic to the MPLS cloud

I need to direct some traffic at the main site with static routes in the router, but I don't want it to be distributed to anywhere else.

Can that be done?

Also, I want ro remove the distribution, but I don't want to disrupt any connection. Can I put static routes in place of the dynamic ones without any problem, while keeping connectivity up?

How would I remove the redistribution and make sure there is constant connectivity.

It is easy with RIP and point to point lines, but I am not sure how to do it with MPLS and OSPF, can I do it?

Thanks for the help

[Richard Burts]

Richard

There are some aspects of your question that I do not undestand fully. Am I correct in understanding that you are running RIP between the router and switches at HQ and running OSPF between the router and the remote sites?

One part of the question seems reasonable clear. You ask about replacing dynamic routes with static routes. You can certainly do it and the process is relatively clear. The routes learned by dynamic protocol will have a certain Administrative Distance (it defaults to 110 for OSPF and to 120 for RIP) and static routes have a different (and more attractive) AD. So if you currently have dynamic routes you can configure static routes for those destinations. The more attractive AD of static routes will mean they replace the dynamic routes in the routing table. When you do show ip route and all the dynamic routes are replaced by static routes then you can remove the redistribution and there should be no impact of that.

Be aware that I said that you could do this. That does not necessarily mean that you SHOULD do this. One advantage of dynamic routes is that they respond to changes in remote parts of the network. If a remote link goes down the dynamic routing protocol should recognize this and update the routing table. If you have configured static routes they do not know about remote changes and will not change.

You know your environment and are the one who can really decide if the change from dynamic to static is appropriate for your network.

Would it perhaps be an alternative to have the router advertise a default route to the HQ switches and not need to advertise the OSPF routes (which would mean that you can remove the redistribution of OSPF to RIP).

HTH

Rick

[richmorrow624]

Thank for the help Rick.

The situation is related to the question you answered about the OSPF routes in the route table.

This situation has multiple problems, one of which is a failover that does not work.

A network engineer on this site was very helpful and thought the mutual redistribution is part of the problem.

Even if It does not solve the failover situation, it seems to be overly complicated.

Here is the situation and I will explain the goal after that:

HQ site:

The switches are only running rip with multiple secondary interfaces and static routes. They are redistributing the static routes to the router.

The switches have a default gateway that is pointing all users to the Internet. There is also a DR site that the switch has a static route to, via broadband cable at the HQ site.

The router is running OSPF and RIP with mutual redistribution to all remote sites. The router gets all static routes via redistribution from the switch, but also has a static route to the DR site thru the cable connection.

We just put a new MPLS site in place at the DR site that ONLY the remote sites are to use for their DR connectivity.

The HQ site is still going to use the broadband cable.

So, I have to point all users at the main site to the DR site via the Broadband cable connection. This is alrady done with the static route.

The problem is, once the MPLS connection is up, that route will be in the HQ site OSPF route table and distributed thru RIP on the router to the switch.

It may not even be a problem because the OSPF route will have a higher AD than the static and the static will take precedence.

I also want to remove the redistribution and don't know how to go about it easily and keep everything connected.

Once I remove the redistribution, there are a lot of routes (static and redistributed)going to get lost I am afraid.