Can rip and ospf work at same time?

[ciscolover]

I think its possible but im not sure... Thanks ¡¡¡

[Peter Paluch]

Hi,

This is a very general question so also the answer can only be very general.

Running both RIP and OSPF in the same network on all routers is possible but does not make much sense. Both routing protocols will build their databases and compute the shortest paths from their own point of view. However, when it comes to deciding which protocol is going to insert its best path routes into the routing table, the OSPF will win by default - its administrative distance on Cisco routers is 110 which is lower than 120 for RIP. In essence, all routes in routing tables will be those of OSPF, and no RIP routes will be present - as if RIP did not run at all.

Running the OSPF in a part of network and RIP in a different part of network is possible, and is seen more often because of several administrative or technical reasons. In that case, for the both parts of a network to "see" each other, at least one router must run both RIP and OSPF, and redistribute - that is, translate - routes learned from one routing protocol into the other.

In any case, just running both RIP and OSPF is technically perfectly possible - they do not interoperate, though, so they will actually not care for each other, nor will they affect each other's operation.

Perhaps if you could make your question more precise we could answer you better.

Best regards,

Peter

[supriyaM]

well expianed

[KapilBains30489]

Can we run (Dijkstra) OSPF on a (Bellman Ford) Rip network? Is it optimal?Will the results be the same? Why or why not? #OSPF #RIP #BellmanFord #Dijkstra

[Joseph W. Doherty]

Unsure about your first question, as in what's a "RIP" network? I.e. RIP and/or OSPF are routing protocols we run on networks, they're not the network itself.

As to your other questions, generally we don't run more than one routing protocol on the same network "covering" the same network segments except in cases when working on a transition from one routing protocol to another. Running more than one routing protocol, against the same part of a network, otherwise, offers little and would normally be consider non-optimal. As far as the results being the same, that depends much on the features of the two routing protocols and how you might have "tweaked" them. For example, RIP "counts" router hops while OSPF "counts" an accumulated path cost. You might configure RIP and OSPF to provide the same results, but often the reason you use a particular routing protocol is due to how it can "see" a network, i.e. different results might be very important to your purposes, such as with OSPF it's often easier to have the routing protocol chose the path with the most bandwidth along a particular path.

[johnlloyd_13]

routing wise, definitely not due to route source's admin distance (AD).

[Peter Paluch]

Hi John,

I agree with you completely - exactly my point. Some mix of RIP+OSPF routes could start to appear if the routing protocols actually started to announce disparate networks (because of route summarization or filtering), or in some other rather convoluted scenarios. In any case, overlaying the existing Layer3 network with two different routing protocols running on each router would always make one of them less trusted (because of the AD), and thus ineffective.

Best regards,

Peter

[Manouchehr]

Well Yes if you do some manipulations ofcourse you can make it work to route set of routes through rip and another set through ospf and redistribute them between each other to get reachablity, but if you turn on the protocol and leave everything to default ospf will take over and rip will only appear if ospf loses adj.

[Peter Paluch]

Hello,

Sure. I guess that speculating about instances when a mix of RIP+OSPF routes would show up in a single routing table does not aid the clarity of this discussion, though, and the original poster should make his query more precise. Otherwise, we're just speculating.

Best regards,

Peter