Can anyone here explain the major routing protocols?  I am looking at learning OSPF, RIP, and IGRP for the CCNA.  I went out and got me a couple of 2501s and the ICND, but I am having some trouble with the different protocols.  I've gotten them all running, but what are the pro/cons of each...

anyone?

Router> reload

What are you trying to do?  Route between 2 internal networks?  Connect to the internet?

Well, right now, I am connecting them to the internet.  I am using RIP to get my routes from my upstream router and I have set the eth0 int to 'passive interface', since I already made the horrible mistake of telling my ISP that I was the route of last resort.  Argh.  Long story. They didn't like that much.  Anyhow, I am looking for examples of both.  I am probably going to focus more on internet, but I am interested in learning about other uses too.

Thanks

Of course, 'routing' protocols are more accurately router communication protocols (that let routers export their routing tables to other routers, figure out the 'best' route, and such...

RIP: The oldest router-communication protocol. There's also a RIP2. Being phased out for OSPF...

OSPF: The current one

IGRP: for routing between external gateways (i.e. connecting 2 separate networks that run different router-control protocols internally)...

That's the 'short version'.

Here are some places that can help:  [url=www.routergod.com/]RouterGod.com[/url], and Cisco's IP routing protocol [url=www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_configuration_guide_book09186a00800ca59b.html]configuration guide[/url]

I think what matters most in your selection of protocol is what protocol(s) your router's neighbors are using.  It won't make any difference to run one protocol if the router's neighbor is running another.

[Edited for clarity]

Hee,hee... Did you ever get running again after telling the local net you were the best path to the internet?? heh,heh... Bet you pissed them off good!

We run OSPF locally, trying to keep individual areas under 100 routers, and BGP accross the core. OSPF is pretty good- though still a work in progress. Its metrics scale well, and convergence is typically quite fast. There are some issues with LSA flooding, but proper area sizing and good route summarization, helps keep it from eating up too much bandwidth.
We use POS or 'packet over sonet' on our Core circuits connecting the  core backbone swouters. Future plans call for gig-e or 10 gig via dark fiber. That should give us lots more headroom as the DWDM gear continues to get lit.
Telemetry is currently using CLNS, Mostly due to a past shortage of IP, but now we plan to IP all the system switches- mostly for better management. Ever try to download an IOS accross a 9600 async oobm connection? Yes? How bout on 6000 individual switches?...
The lab is working with terrabit-e. its been up now for about 6 months- Boston to Denmark to NY,NY. So far so good.
I'm still waiting for the holographic protocols to show up! heh,heh...

Now for your question- For your CCNA all you will be asked about is RIP/IGRP and maybe 1 or 2 questions on EIGRP or OSPF. It is the world according to Cisco, so only Cisco routing protocols will be focused on. Spend your time there.

[8D]

Do you have access to the book "Interworking with TCP/IP" by Comer.  Its one of the standard references in the equipment provider industry.