EIGRP or OSPF

[g.peart]

I'm currently running a network of 40 routers using EIGRP. I've been told to move to OSPF since EIGRP is non-standard. I use OSPF on our firewalls which aren't cisco

and redistribute. Are there any compelling reasons for using OSPF over EIGRP ?

[s.salimpoor]

I think EIGRP is much more better than OSPF,faster convergence and easy configuration are just some of the benefits of it. however ospf is a standard-base protocol and you can run it on eny device.

[ankurbhasin]

Hi All,

It all depends on your network requirement and choice. No dount ospf is a good in some aspects like its a multivendor protocol and work well and you need not redistribute from your firewalls.

Also if you configure using its hirarchical nature configuring different areas any topology change in some area will not affect other areas and will not let other areas to converge and do all the recalcultion again.

In eigrp any topology chanbe will affect all the routers and all the routers have to converge and do the recalculation again and can create a delay in network.

But no doubt eigrp is a very simple protocol compared to ospf and very easy to configure and fine tune and if you have all cisco products in network you can go ahead with EIGRP.

HTH

Ankur

[ruwhite]

"Also if you configure using its hirarchical nature configuring different areas any topology change in some area will not affect other areas and will not let other areas to converge and do all the recalcultion again.

In eigrp any topology chanbe will affect all the routers and all the routers have to converge and do the recalculation again and can create a delay in network."

With OSPF, if you are not aggregating at the ABR (at the area border), then changes within an area will still be propagated throughout the entire network, since the type 3's generated by the ABR's will change when anything within the area changes. With OSPF, then, the only way to really prevent changes from propagating throughout the network.

With EIGRP, anyplace you aggregate, you block changes from being propagated through the network.

In the end, then, EIGRP and OSPF both block propagation about changes in the network at the same place--wherever you aggregate routing information. One difference here is that you can aggregate (or summarize) in one place in OSPF--at ABRs. Since ABRs only exist at the area 0 edge, you can summarize, end to end, in your network, at two places at the most. EIGRP has no limitations on where you can summarize.

There are many good and bad points about each protocol.

:-)

Russ.W

[amit-singh]

Hi,

Both the protocols have trie own advantages and disadvantages. As mentioned in earlier port OSPF is a standard based so you can use it in multivendor environment while EIGRP is Cisco Proprietry.

With OSPF you can define a Hierarchical Topology and divide you routers into multiple areas which led to low memeory requirement, low CPU utilization due to internal routes with in the area and less number of routes propogated to areas using Stub areas. Although EIGRP doesnot support Hierarchical Topology but it has an Auto-summarization which results again in Low memory requirement and low CPU utilization.

EIGRP can be configured for unequal cost path load-balancing while OSPF only does equal cost path load-balancing.

Both the routing protoccls just send the updates only when there is some change in the topolgy. However EIGRP share its entire routing table when it first comes up and then only the changes are sent while OSPF is a pure link state protocol and change share the LSA/s to populate its routing table and then run the SPF to find the shortest route.

Both the routing protocols support Stub routing.

So I think the only reason you have been asked to move to OSPF just to use in a multivendor environment.

HTH,

-amit singh

[npagadua69]

i both agree with Ankur & Amit. EIGRP is a cisco proprierotory and OSPF is multivendor environment. we also want to keep in mind that its easier to troubleshoot an EIGRP as opposed to an OSPF environment.

neil

[ruwhite]

"With OSPF you can define a Hierarchical Topology and divide you routers into multiple areas which led to low memeory requirement, low CPU utilization due to internal routes with in the area and less number of routes propogated to areas using Stub areas. Although EIGRP doesnot support Hierarchical Topology but it has an Auto-summarization which results again in Low memory requirement and low CPU utilization."

Or manual summarization, not just auto-summarization.

"Both the routing protocols support Stub routing."

Well, OSPF supports stub areas, while EIGRP supports stub routers. These are completely different concepts.

:-)

Russ.W