OSPF and EIGRP neighborship establishment time.

abdul 17717

Guys,

Does any one know how much time does it take to form complete neighborship status between 2 routers (OSPF and EIGRP)? I am not talking about the hello, or keepalives. I need the time that it would take to form the full neighborship from the moment the 2 routers are connected to the moment they start routing through each other.

hurricane1091

Can I ask why you are asking? I believe it's instantaneous. Okay, there are stages to go through first so it can't be instantaneous (OSPF for example: Initializing, picking master/slave, exchanging DBD's...) but it can't be very long either.

networker050184

You should be thinking of hello times. This can also be important in neighbor formation. OSPF for example neighbors are formed using hello packets. After that you have the database exchange which the time varies obviously with the size of the database, how many full LSAs in that database need to be exchanged, not to mention router resources to do these things. So there really isn't a hard set time that is absolute. If you want a baseline for your network some testing would be in order under your exact hardware and conditions.

abdul 17717

Because I have an idea that I really believe that could make it faster.

abdul 17717

so about 3-5 seconds in average? (if we are talking about a significantly large db)

networker050184

That seems longer than the average I have seen though I haven't really timed it. Why not just lab it up and test it out?

OfWolfAndMan

The only things that really matter for troubleshooting suboptimal convergence in this situation is the router's load (Which should be barely any if it's just two routers lol) and the physical link itself (Speed, full or half duplex), or maybe the link has some kind of intermittent unidirectional link issue. Even then, it's still fast for EIGRP and OSPF. BGP and RIP are the slow ones