Path: utzoo!censor!geac!yunexus!ists!eric From: eric@ists.ists.ca (Eric M. Carroll) Newsgroups: comp.dcom.lans Subject: Re: Problem DELNI <--> HP lan analyzer Keywords: DELNI, HP4972A, collisions, lan analyzer Message-ID: <769@ists.ists.ca> Date: 24 Aug 89 06:45:34 GMT References: <863@cgch.UUCP> <2545@orion.cf.uci.edu> Reply-To: eric@ists.ists.ca.ists.ca (Eric M. Carroll) Organization: Institute for Space and Terrestrial Science Lines: 22 In some randomly numbered article meggers@orion.cf.uci.edu (mark eggers) writes: >Another way to shut off the heartbeat is to plug in an Ethernet 'loopback' >connector into the network port. Then tell the DELNI that it is attached >to a network. No heartbeat from the network - no heartbeat on the DELNI. > >The connector should have been a part of your DELNI package. We found out >about this at Notre Dame when we started to plug DEMPRs into standalone >DELNIs. Performance was terrible. Connecting the loopback connector and >switching the DELNI to network connected mode solved the problem. Now this is fascinating. About 6 months ago I inherited a problem where I had 3 Cabletron repeaters pluged into a DELNI (a Cabletron MT-800) in LOOPBACK mode with heartbeat (SQE) OFF. There is no known chapter and verse outlawing it, but everyone I discuss this with says *yuck*. Cabletron said it should work. But I consistently achieved 50% packet loss rates through two of the three legs. I eliminated all possible combinations of cables, repeaters fiber modems and DELNIs. Nothing worked. Finally I eliminated the DELNI and replaced it all with a multimedia multiport repeater. That solved my problem.