Newsgroups: comp.dcom.sys.cisco
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From: viktor@shearson.com (Viktor Dukhovni)
Subject: bridging FDDI
Message-ID: <1991May26.165659.4362@shearson.com>
Sender: news@shearson.com (News)
Organization: Lehman Brothers
References: <35356@boulder.Colorado.EDU>
Date: Sun, 26 May 91 16:56:59 GMT

William "Chops" Westfield <BILLW@mathom.cisco.com> writes:

>local media.  Cisco currently doesn't support transparent bridging to
>or from FDDI at all - while not conceptually difficult, transparent
>bridging potentially requires filtering (discarding) FDDI packets
>at media rate (400k pps or so).  This can be done with special hardware,
>but it's a bit beyond the capability of even the RISCy VLIW buzzword
>buzzword bitslice processor on cisco's current FDDI card.  In addition,
>the FDDI chipset needs to be able to tell which frames to strip from
>the ring, even though neither the source nor destination address matches
>the local address.  This capability is not present in the current
>implementation either (ah, the curse of being first).  So transparent
>bridges ought to interoperate ok, but they aren't common yet.

	Can one conclude this means that "helper-address" and ip flooding are 
not available for FDDI?
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