Where do you see Routing Protocols?

Question

Hello,

I am about to study for the CCNP Certification exam and the first section is all about routing protocols. I am understanding the material but I am having trouble understanding where all this is really implemented. When I hear about EIGRP, I look it up on youtube and I see someone typing in code, like here for example:

http://www.youtube.com/user/MrHesiadmin#p/search/0/cWTwJQgl3EQ

I just want to know what code this is even for, my guess is programming a router? And I would like to know where routing protocols would be important to me. Thank you for anyone who has an answer for me.

Answer 1

Routing protocols are used when networking many routers together. The routers communicate with each other through routing protocols such as EIGRP, OSPF, RIP, BGP etc. to exchange information on how to get to any given subnet. Typically a router will have both LAN and WAN ports. It uses the routing protocol to "advertise" its LAN subnets to other routers on the WAN. That info is propagated throughout the network so that all the routers know how to get to any advertised subnet.



The alternate to using routing protocols is to use static routes where the network admin manually adds routes to each router. After about 3 routers this becomes cumbersome and labor intensive. Routing protocols save you all that hassle and can re-route if a WAN segment fails.



In a Cisco router, you will find them in the configuration after the interfaces and before the access lists.



EDIT: To access the router and configure it from a command line you can either connect to the router's console port or telnet to it. Using the console port requires a special cable and you need a terminal program like Procomm. To telnet all you need is an Ethernet connection. On your PC, go to Start, Run and type in cmd. In the command window, type in: telnet . You will have to enter a password.



Hope this helps. Your profile does not permit email.

Answer 2

You don't see the protocol directly unless you are sniffing the wire.



What it is used for is to define internal routing (or external routing). How are you

going to say route packets through a tunnel? You should be able to tell all routers that the tunnel exists, and how to get there without having to install static routes everywhere.



So when you "program" a router, it is telling how to join the internal routing protocol, and how to advertise and use routes.

Answer 3

I am not completely sure about all the specifics of EIGRP, but routing tables in general are used to create forwarding tables for the router. the commands he was typing in that video were to setup a tunnel between multiple points, so the connection would use that instead of going through multiple hops and having to check each packet's info

Answer 4

If there is no routing protocol how can any routing happen?

Answer 5

How you configure a router would be dependent on the manufacture of the router. For a typical cisco router you might see something like"



interface eithernet e0/0

ip address 10.0.0.1 255.255.255.0

no shut

!

interface eithernet e1/0

ip address 10.1.0.1 255.255.255.0

no shut

!

router eigrp 4453

network 10.0.0.0

!



there are of course a lot more complex configs depending on deployment, but that is the jist of it...