Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!usc!orion.cf.uci.edu!meggers From: meggers@orion.cf.uci.edu (mark eggers) Newsgroups: comp.dcom.lans Subject: Re: Problem DELNI <--> HP lan analyzer Summary: DELNI <--> HP lan analyzer Keywords: DELNI, HP4972A, collisions, lan analyzer Message-ID: <2564@orion.cf.uci.edu> Date: 28 Aug 89 16:43:47 GMT References: <863@cgch.UUCP> <12089@ulysses.homer.nj.att.com> Organization: University of California, Irvine Lines: 28 As has been pointed out, this problem only occurs with the DELNI multiport transceiver. The problem is that you cannot configure heartbeat as you would like. In the DEC manuals, there is a warning about plugging DEREPs into DELNIs (repeaters into multiport transceivers). Since DEMPRs (multiport thinwire Ethernet repeaters) count as a repeater [I think], plugging a multiport thinwire repeater into a DELNI causes problems unless the DELNI is plugged into a nonheartbeat generating transceiver (H4000 from DEC is one example). Since the cascading of up to eight DEMPRs on a DELNI is part of the DEC wiring plan, the fact that this won't work without either attaching the DELNI to an H4000 transceiver (documented) or using a loopback connector on the ninth port (UNDOCUMENTED) is a bit annoying. Please note that the above incompatibilty (hearbeat vs. no heartbeat) is only a problem with DEC DEMPRs (thinwire multiport repeaters), and DELNIs (multiport transceivers) as far as I know. The corresponding Cabletron setup (MR-9000s and MT-800s) can be configured to work (heartbeat is configurable on the ninth port). Disclaimer: UCI is not responsible for the nonsense that I may post on the net. I am just a user of both DEC and Cabletron equipment. Thanks goes to the DEC technical support pointing out what I needed to do to get things running. /mde/