Rip vs EIGRP or OSPF

chill8888 · ‎03-02-2010

We are currently running rip ver 2 on our Cisco network. We are discussing moving to EIGRP. Is that still the recommended routing method & can it be implemented on several routers at a time or does everything have to be switched over at once? Should OSPF be considered?

Thank You,

Carolyn

Brent Rockburn · ‎03-02-2010

If you are all cisco than EIGRP is a good way to go.

Jon Marshall · ‎03-02-2010

Carolyn

A question that may well get many different answers

I have used EIGRP quite extensively and it works well but only if you can summarise effectively between sites. If you can't then you can start to get SIAs (Stuck in active) as queries can traverse the entire network. With EIGRP stub and summarisation it can be a very effective protocol and if you have redundant paths in your network it is very fast to fail over. It is easier to configure than OSPF in my opinion or at least it has fewer options to worry about

As for OSPF, well by it's nature it imposes organisation on you, assuming you are not just going to use one area. Summarisation is still important but OSPF only propogates certain routes between areas anyway. It is a more complex protocol than EIGRP and requires more initial planning but that doesn' mean you shouldn't consider it.

The big advantage to OSPF is that it is not Cisco proprietary unlike EIGRP. An example would be that non Cisco firewalls do not support EIGRP but most do support OSPF. So if you need to exchange routes with other vendors equipment OSPF is often the better choice.

Jon

chill8888 · ‎03-02-2010

Thanks for your reply Jon.

If we continue to run rip v2 on edge routers along with eigrp, would we then be able to communicate with other vendor equipment? Also, can eigrp be implemented several routers at a time or do they all have to be done at once?

Thank You,

Carolyn Hill

Jon Marshall · ‎03-02-2010

chill8888 wrote:

Thanks for your reply Jon.

If we continue to run rip v2 on edge routers along with eigrp, would we then be able to communicate with other vendor equipment? Also, can eigrp be implemented several routers at a time or do they all have to be done at once?

Thank You,

Carolyn Hill

Carolyn

You could use RIP v2 to talk to other vendor equipment and then redistribute into EIGRP and vice-versa but if you have to do a lot of this it may well be more trouble than it is worth. Bear in mind also that RIP has limitations in hop count ie. > 15 hops and the route is unreachable so you would need to work out how many hops could be involved.

As for implementing several at a time. The problem you have is that EIGRP has a better AD than RIP so any routers configured with EIGRP would start to use the EIGRP learnt routes. What you can do is configure all routers with EIGRP but temporarily increase the AD for all EIGRP routers to be greater than 120 (RIP routes). This will then allow you to add EIGRP onto all routers without affecting current routing. Once you are happy that all routes are known by EIGRP you can then remove the RIP process and set the AD back to it's original ie. EIGRP internal = 90, EIGRP external = 170. As long as your routers can temporarily support running 2 routing protocols you should be fine.

But i would emphasize that if there is a lot of other vendor equipment you need to exchange routes with using RIP and EIGRP could make for very messy configs compared to simply migrating to OSPF.

Jon