a comment or two below: ""Ather Iqbal"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > Hello group, > > Interior Gateway Protocols (IGP) are used to exchange routing information > with routers in the same autonomous system. Examples are OSPF, IGRP, EIGRP, > RIP (right ?).
CL: sure. the term "autonomous system" sometimes causes confusion. organization, company, might be considered synonymous. > > Exterior Gateway Protocols (EGP) are used to communicate between ASes. > Example will be BGP (right ?). CL: about the only example, these days. anyone ever seen any documentation of the protocol EGP on CCO? > > The reason I am confused is because of iBGP, eBGP and also external EIGRP. > Now I am quoting from Sybex "The internal Border Gateway Protocols used by > routers that all belong to the same AS. So where does iBGP fits in. Is it an > IGP or EGP? Similarly what is external EIGRP? Even an important question > will be; in real life where would one like to use iBGP CL: now you are into an area where there can be confusion unless you clearly differentiate between and EGP and an IGP. CL: BGP is used to communicate reachability between and among different "autonomous systems" or "internet providers" or "companies" Between/among these organizations one uses eBGP. But if a single organization has more than one BGP router, these routers use iBGP to communicate. The purpose is to eventually provide information to external groups, if you will CL: on the other hand, OSFP and EIGRP have built into them a recognition of routes whioch are not native to the protocol, but come into that protocol via redistribution. So let's say my company is running EIGRP, and we merge with another company that is running OSPF, I and my counterpart at the other company determine we have no overlapping subnets, so we decide to make our lives easier by setting up a single router between the two organizations, and on that router we redistribute between EIGRP and OSPF. My routers now see all the formetr OSPF routes as "EIGRP external" and the guy at the other company sees all my EIGRP routes as either OSPF type 1 or OSPF type 2, depending on what we choose to do. > > > Could some body point me to an online resource for BGP that is easy to > follow. I am having hard time understanding chapters 8 and 9 in Sybex > Routing Study Guide. CL: JMHO, but I've seen some very poor writing and a fair share of erroneous infomration in Sybex books. Not surprising, based on a certain personal experience I had with Sybex editors a while back. CL: BGP is really very simple. But all the fun / useful knobs can become very difficult. Kinda like the game Othello,. A minute to learn, a lifetime to master. I don't have the link any longer, but somewhere on CCO resides the original BGP paper that Bassam Halabi wrote, and which became the basis of his book. It's about 80 pages, and very good. Maybe someone recalls or has the link bookmarked? Over the years I've posted it more than a couple of times. > > > Kindest Regards, > > > Ather Iqbal > > > -------------------------------------------------------------------------- ----------------------------------------- > > . This email and any files transmitted with it are confidential and > . intended solely for the use of the individual or entity to whom > . they are addressed. > . If you have received this email in error please notify the > . originator of the messageand the system manager at > . [EMAIL PROTECTED] and delete the material from your computer. > > . This footer also confirms that this > . email message has been scanned for the presence of computer viruses. > > . Any views expressed in this message are those of the individual > . sender, except where the sender specifies and with authority, > . states them to be the views of Pharmaceutical Solutions Industry. > > 7 Finally, the recipient should double check this email and any > 7 attachments for the presence of any viruses. > 7 Pharmaceutical Solutions Industry accepts no liability > . for any damage caused by any virus / error transmitted by this > email." > > -------------------------------------------------------------------------- ----------------------------------------- Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=51558&t=51558 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
