Re: Re: Routing protocols, Internet vs Enterprises

Very much in agreement there, even in a simple network routing protocols can 
produce a lot of benefit even if only through simplified provisioning of new 
sites/ports etc.

To the original poster, there's been some weird misleading responses here - 
though the Wikipedia links are good. 

Take a step away from thinking of routing protocols as intended for Internet or 
Enterprise use. Various protocols can be used in both situations but for 
different reasons and within different contexts.

Having worked for ISP's, in particular those using MPLS and integrating 
customers using various routing protocols it is not uncommon for an ISP (a 
segment of the Internet) to use OSPF, EIGRP, ISIS and BGP simultaneously.

Think rather that different protocols are used for doing different things. 
Choose the best available tool for the job so to speak.

BGP (an EGP) is intended for use when interconnecting different networks 
(AS's), whether they be different ISP's or different segments of a 
multinational company. It's basic purpose is to provide information about a 
network and about a *possible* path to that network.

OSPF, EIGRP, ISIS and other IGP's are intended for use within a single network 
(AS) in order to provide information about the best route (or routes) to 
specific subnets or hosts within the network.

That's my two cent brain fart summary of the difference anyway. RIP and IGRP 
are no longer of much relevence to anyone unless you're studying for a CCNA or 
similar certification.