Well now, wouldn't that be interesting - an ISP that didn't run an IGP.... Hmmm..... In fact, no less an authority than Radia Perlman has touted the merits of a single unified routing protocol that could be used for both intra- and inter-domain routing. For those who don't know who she is, Ms. Perlman is one of the living legends of protocol design. For example, she was the principal designer of spanning-tree and ISIS, and NLSP. She also formulated much of the early work of link-state protocol algorithms that are the basis of OSPF and PNNI. She laments how we have gotten to the status quo of having separate intra and inter-domain protocols.
But in answer to your direct question, the answer to your question is that because ISP's must have some way to do their interior routing, that almost always means an IGP is required, although I suppose in theory they could just use static routes, although I have yet to run into one that does that. ISP's often run BGP, but not always - for example, I've worked with some mom+pop ISP's. that don't run BGP. If they do run BGP, it is "no-synced". A new service-provider initiative that is being pushed by Cisco and other vendors is to run BGP only on edge routers and have a BGP-less core that is transited purely by label-switching. A dicey proposition if you ask me, as I would think that providers are loathe to give up the control that BGP offers. ""Steven A. Ridder"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > Hey guys and gals, > > I have never worked in an ISP, so I have no idea how they run. I'm just > curious, do they run an IGP in addition to IBGP and is it fully > synchronized? I'm just curious to see how it's done in the real world. > > -- > > RFC 1149 Compliant. > Get in my head: > http://sar.dynu.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=38619&t=38614 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
