Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!zaphod.mps.ohio-state.edu!magnus.acs.ohio-state.edu!csn!boulder!recnews From: Watt-Alan@mickey.ycc.yale.edu Newsgroups: comp.dcom.sys.cisco Subject: Re: backplane backbone, routing or bridging? Message-ID: <9106241714.AA12454@mickey.ycc.yale.edu> Date: 24 Jun 91 17:14:57 GMT Sender: news@colorado.edu Organization: University of Colorado, Boulder Lines: 61 Return-Path: From Alan Watt's correction to his original mistaken posting: >> likely to get you in trouble. However, I am quite sure that nothing >> stops you from getting yourself a new class C network and subnetting >> it as described above. This still saves you from wasting unnecessary >> subnets of your class B. >> From Mark Tassinari's response to the above: > >Possibly, there is. We just installed routers in the same configuration and >were faced with the same decisions. Page 5-5 of the manual states " ...the >network must be set up such that it does not require traffic between any two >subnets to cross another network." > >For the diagram below this would prohibit the use of a new class C network >number for the point-to-point links. > > net 128.115.1.0 128.115.2.0 > | | > | | > -------- ------- > | cisco | | cisco | > -------- ------- > \ / point-to-point > \ / links > \ / <----- > ---------- > | backbone | > | cisco | > ---------- > >We finally decided to burn a subnet for each link (fortunately there were only >10). I hope we will be into the next generation technology by the time we need >those subnets, and that new technology will involve a topology change (like >FDDI). > I should have just kept my mouth shut. You're right; my "fix" for the original mistake was no better. Forget I said anything. However, *I AM ABSOLUTELY, POSITIVELY, CERTAINLY CONVNICED* there is *NO TECHNICAL REASON* why you can't just get a class A address, and subnet it on a 255.255.255.0 boundary. This will give you 8-bit subnets coming out of your ears. Too bad the NIC won't give them out so freely. Aha! maybe I've finally figured out why we need OSI!! :-). - Alan S. Watt High Speed Networking, Yale University Computing and Information Systems Box 2112 Yale Station New Haven, CT 06520-2112 (203) 432-6600 X394 Watt-Alan@Yale.Edu Moral: Measure *thrice*, cut once. or: It is better to remain silent and be thought a fool than to speak up and remove all doubt.