Xref: utzoo comp.dcom.lans:2895 comp.protocols.tcp-ip:7288
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uflorida!ukma!robert
From: robert@ms.uky.edu (Robert Lee)
Newsgroups: comp.dcom.lans,comp.protocols.tcp-ip
Subject: Re: bridges & address filtering
Message-ID: <11805@s.ms.uky.edu>
Date: 31 May 89 22:43:45 GMT
References: <3407@ursa-major.SPDCC.COM>
Reply-To: robert@ms.uky.edu (Robert Lee)
Organization: U of Kentucky, Communications Services, Networking.
Lines: 35

We've had some experience with bridges at UK.  For the most part we use
them to isolate the various ethernets on campus from the broadband backbone.
Currently we use the UB-DLB and LAN-100 bridge, the latter had a bug.
if someone used a destination address of all 1's FFFFFFFF the routing table
would get trashed.  It turned out the LAN-100 was using FFFFFFFF as the
terminating entry for the routing table...  We also use the 
UB DLB(Data link bridge) with no problems.  We have a limited set of
management capability for these bridges and would like to have much more.

With the UB DLB we can program filters bi-directionally but not 
uni-directionally.  It would be nice if we could do this with a bridge
also it would be *very* nice if there was a extensive set of tools that
would work with bridges at the network management level. 

For example here are some things I would like to be able to do with
a bridge.

1) Be able to tell the bridge to disconnect from a ethernet for a time
   or until I tell it to turn its packet forwarding back on.
2) Be able to tell the bridge to forward all the packets it sees.
3) Programmable filters that don't degrade packet forwarding to any high 
   degree.
4) A extensive set of statistical variables.  Like # packets/sec. Collision
   etc etc.  Also it would be nice if these results could be put into
   a file that can be processed with statistical programs like SAS or SPSS.
5) Bridges usually only look at the ethernet address header and
   not what type of packet it is.  It would be nice if there was a facility
   that allow the bridge to forward based on packet types.  I can do
   this to some extent with filters now.

Anyway, that's what I would like for a bridge.   

Robert Lee
SYSBOB@UKCC
University of Kentucky