As Peter van Oene stated, while this assumption (that ISP's run pure Cisco) might have been valid a few years ago, it is not a valid assumption now.
For example, according to Boardwatch magazine, in 2001, the top 9 biggest ISP's, by traffic are as follows: 1) MCI-Worldcom (UUnet) 2) AT&T 3) Sprint 4) Qwest 5) Genuity 6) Cable&Wireless 7) Verio/NTT 8) Psinet 9) Savvis Of those 9, 7 of them are known Juniper customers (only AT&T and Sprint are not). Not to mention the other vendors like Unisphere, Pluris, etc. So clearly EIGRP won't fly in these networks. ""Jeffrey Reed"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > Is it a good assumption that most ISP's, big & small run Cisco routers in > their core networks? If so, why don't they use EIGRP? I've run into so many > Cisco routers guys in corporations who threaten holy wars when you ask them > to move to standards-based OSPF. They claim EIGRP runs more efficiently on a > Cisco router than OSPF... less memory, less CPU etc. If this is correct, why > don't ISPs run that as their interior routing protocol? > > Jeffrey Reed > Classic Networking, Inc. > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Peter > van Oene > Sent: Sunday, March 17, 2002 8:35 PM > To: [EMAIL PROTECTED] > Subject: Re: IGP's in ISP [7:38614] > > ISP's typically run one of IS-IS, or OSPF as their IGP's and manage only > link and loopback address space within it. IBGP is always fully meshed, > although most use tools like Route Reflection and Confederations to avoid > the n*(n-1)/2 scaling issues IBGP can present. Synchronization is an > antiquated feature that hasn't been turned on in production ISP's for > years. Most new routing implementations do not even include the > functionality in their BGP code. > > An overall design theory is to keep the IGP as small and efficient as > possible to as to maximize convergence, and to keep everything else in BGP > where rich tools like community based policy can be leveraged fully. > > pete > > > At 05:52 PM 3/17/2002 -0500, Steven A. Ridder wrote: > >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=38710&t=38614 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
