Hi,

First time poster looking for some input on a debate and I apologise if I've

done this completely wrong, but I don't think my colleague will be convinced

until he hears it from this community.

Granted I'm relatively green when it comes to networking, but it was my

understand that other than BGP, the most widely used/implemented IGP  would be

OSPF. However, my colleague insists that I'm 100 percent wrong and that is

IS-IS.

I want to be clear, I'm not debating which protocol is better or worse, as they

both have their strengths and weaknesses and ultimately it comes down to several

factors based on a particular use-case on which routing protocol is the best way

forward for a network.

However in saying that, I believe that, when it comes to sheer numbers of where

an IGP is implemented, OSPF is far more widely used in the world today, whether

it be in small to medium to large businesses, Enterprise networks and even

Service Provider networks (where as per my understanding, is where IS-IS really

shines)

I understand that this isn't really quantifiable, but I would like to get the

opinions/experiences from this list and see what the outcome of this question is

out of sheer curiosity.

Thanks!

Steve