When I used to work at UUNET (now Worldcom) they used ISIS as their IGP. Here at BT, OSPF is used.
-----Original Message----- From: Ladrach, Daniel E. [mailto:[EMAIL PROTECTED]] Sent: Monday, March 18, 2002 14:00 To: [EMAIL PROTECTED] Subject: RE: IGP's in ISP [7:38614] On our backbone we use Juniper routers. Also, we do not run OSPF either. Daniel Ladrach CCNA, CCNP WorldCom -----Original Message----- From: Jeffrey Reed [mailto:[EMAIL PROTECTED]] Sent: Monday, March 18, 2002 7:22 AM To: [EMAIL PROTECTED] Subject: RE: IGP's in ISP [7:38614] 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=38657&t=38614 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
