At 4:09 PM +0000 12/2/02, p b wrote: >Thanks. I had expected that "router bgp ABC" and "router bgp XYZ" >did in fact start two processes. I hadn't tried applying a >second "router bgp XYZ" to a config to confirm this worked. But >as you point out, this isn't allowed (supported) and the router >reports the error: > >router(config)#router bgp 1234 >BGP is already running; AS is 123 > >I'm surprised that multiple IS-IS processes are not supported (but >I don't know diddley about IS-IS so...) Any thoughts on why >cisco decided to support multiple OSPF processes (or why other >vendors did not)?
There's a lot of things unclear about Cisco's early OSPF. The first versions really didn't work, until a major rewrite about IOS 9.1(4). I don't know if Derek Yeung took it over then or later, but, until he left Cisco, was the main OSPF programmer. I don't know if the multiple processes were one of the original ideas, possibly to preserve some of the pseudo-area feel of IGRP. ISIS always worked, but it has a special advantage: almost every major implementation (early NSFNET and other research implementations, Cisco, and Juniper) were all designed and mostly coded by Dave Katz. These are just guesses. It is worth looking at putting a Zebra/LINUX box or two in your lab for extensive route generation, including routes with errors. Probably cheaper than non-EOL routers. Zebra is free. > > > > >Howard C. Berkowitz wrote: >> >> At 12:34 PM +0000 12/2/02, bergenpeak wrote: >> >Anyone know why one can run only a single RIP process on a >> cisco >> >router? >> > >> >Thanks >> > >> >> I can't give you a precise reason, but some general comments. >> >> RIP was never intended for large systems where you might be >> able to >> make use of multiple processes. You could argue that having >> multiple >> IGRP processes was a way to add a primitive area structure, and >> then >> EIGRP needed compatibility. >> >> Even among the more advanced protocols, the multiple process >> per >> router has rather little applicability. OSPF is actually the >> exception in allowing multiple processes; BGP and ISIS do not. >> >> AFAIK, no vendor other than Cisco ever implemented multiple >> OSPF >> processes. Wellfleet/Bay/Nortel definitely did not. >> >> For things like performance benchmarking for the IETF and such, >> we >> most typically use Zebra or GateD UNIX boxes to generate >> traffic, or >> purpose-built high-speed testers. The high-speed testers >> typically >> don't really understand the protocol, but are playing back >> prerecorded traffic and responding to a very small set of >> messages. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=58405&t=58392 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
