Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!apple!hercules!cslb.csl.sri.com!cire From: cire@dustbin.cisco.com (Eric B. Decker) Newsgroups: comp.dcom.sys.cisco Subject: Re: Cisco Router Protocol Message-ID: Date: 8 Apr 90 23:15:13 GMT References: <9415@cbnewsh.ATT.COM> <17201@hercules.csl.sri.com> Sender: usenet@csl.sri.com Distribution: comp Organization: cisco Systems Lines: 68 In-reply-to: forster@cisco.com's message of 6 Apr 90 18:38:32 GMT In article <17201@hercules.csl.sri.com> forster@cisco.com (Jim Forster) writes: >> And finally, what do the routers do to route in networks with >> multiple routing protocols (e.g. IGRP and RIP, to pick an example, >> or OSPF and RIP for a harder (?) example). Assume a topology that >> admits a non-trivial answer! Okay. I'll answer this one. cisco provides the tools to do this. However because of the differences in Routing protocols it is very easy to hammer your network in a big way. ***THIS IS NOT RECOMMENDED!*** But we are aware of the need in many cases to allow multiple routing protocols to exist in the same network. One example is communicating routing information to a node running routed or gated. Since these daemons don't know about IGRP some other protocol needs to be used. The mechanism supplied is the redistribute command. I don't have the syntax memorized and I'm at home without a manual so I'll have to refer you to the manual and release notes. Basically the idea is to selectively release information learned from one routing protocol to another. But once again you have to be very careful here because it is very easy to introduce non-optimal routes and routing loops. Earlier routing protocols are different from the more modern ones such as IGRP and OSPF and won't have the same level of information embedded. Result: less informed routing decisions. I mentioned the need to communicate to a node running gated or routed. There are better mechanisms that allow communications of information to these nodes. Namely GDP (Gateway Discover Protocol, gateway in the sense of a router). Having hosts involved in routing decisions is in general a bad idea. However there are still some things that it needs to find out and GDP supplies this information. cisco routers have a GDP implementation and we have a reference non-supported Unix implementation of a gdp daemon that can run on Suns. If you need further information about cisco products please feel free to send a message to customer-service@cisco.com. thank you, -c cire|eric "I could have done it in a much more complicated way", said the Red Queen, immensely proud. -- Lewis Carroll, Alice in Wonderland Eric B. Decker Token Ring Development cisco Systems - engineering Menlo Park, California email: cire@cisco.com uSnail: 1525 O'Brien Dr., Menlo Park, CA 94025 Phone : (415) 326-1941, (415) 688-8241 -- cire|eric "I could have done it in a much more complicated way", said the Red Queen, immensely proud. -- Lewis Carrol, Alice in Wonderland Eric B. Decker Token Ring Development cisco Systems - engineering Menlo Park, California email: cire@cisco.com uSnail: 1525 O'Brien Dr., Menlo Park, CA 94025 Phone : (415) 326-1941, (415) 688-8241