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From: karn@FLASH.BELLCORE.COM.UUCP
Newsgroups: mod.protocols.tcp-ip
Subject: Re: Response to anti-bridge comments
Message-ID: <8703301843.AA24737@flash.bellcore.com>
Date: Mon, 30-Mar-87 13:43:22 EST
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Posted: Mon Mar 30 13:43:22 1987
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DEC LanBridge 100's have a loop detection algorithm.  When a bridge is
turned on, it sends out test packets on each interface and checks if they
come back in on the other side. If so, the bridge will remain offline and
not forward traffic.  An offline bridge will continue to test the path and
will go online within a few seconds should the existing path fail.

It is my understanding that while the Vitalink Translans have a similar loop
detection algorithm, not every combination of DEC and Vitalink bridges will
do what you want. If there are parallel paths via LanBridges and Translans,
it's possible to have a LanBridge go offline in favor of a Translan, which
is decidedly suboptimal.  I understand Vitalink is working on a new software
release that will "do the right things" in combination with LanBridge 100s.
Fortunately the situation is rather rare (it doesn't occur in our network).
For further info you should call Vitalink.

Phil