Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!mips!pacbell.com!tandem!netcom!jbreeden From: jbreeden@netcom.COM (John Breeden) Newsgroups: comp.dcom.lans Subject: Re: 10Base-T hubs Message-ID: <1991Apr16.182217.6151@netcom.COM> Date: 16 Apr 91 18:22:17 GMT References: <1991Apr10.150801.2519@ux1.cso.uiuc.edu> <1991Apr15.214932.9635@jhereg.osa.com> Distribution: usa Organization: Netcom - Somewhere in the S.F. Bay Area Lines: 60 In article <1991Apr15.214932.9635@jhereg.osa.com> andrew@jhereg.osa.com (Andrew C. Esh) writes: >In article <1991Apr10.150801.2519@ux1.cso.uiuc.edu> german@uxh.cso.uiuc.edu (Gregory German) writes: >> >>Even though we don't use it in most cases I have also designed in the ability >>to add intelligent monitoring tools to the the hubs. LANview with Cabletron >>repeaters and an module with SNMP capability in the Plexcom chasis. I expect >>to see increased use of these as tools become available. >> >>> - RL "Bob" Morgan >>> Networking Systems >>> Stanford >>-- >> Greg German (german@sonne.CSO.UIUC.EDU) (217-333-8293) >>US Mail: Univ of Illinois, CSO, 1304 W Springfield Ave, Urbana, IL 61801 >>Office: 129 Digital Computer Lab., Network Design Office > >Yes, and the David box, as well as the Xyplex Communications Server both >have SNMP modules also. Real nice, since that means one's pink little butt >and one's cushy office chair don't have to part company in order to figure >out where the problem is. :-) Two thumbs up for SNMP. >-- >Andrew C. Esh andrew@osa.com >Open Systems Architects, Inc. >Mpls, MN 55416-1528 Punch down, turn around, do a little crimpin' >(612) 525-0000 Punch down, turn around, plug it in and go ... I've been paying around with a new hub - AT&T's "smart" hub - includes an SNMP agent (save the pink little but from work) and also has another in- teresting feature - security. These hubs know about every MAC address attached to each port. Press a button on the SNMP monitor and it draws a graphic map of all the hubs and each and every MAC address attached to it, I can build and alias file of the MAC addresses (x-ref'd to domain names) - but that's not the best part. If someone unplugs their box and moves, the map instantly shows his new location (wow! a REAL TIME physical map! - with addresses!). I can let the guy (or gal) stay at the new location or block him! - automatically! As a matter of fact, I can block ANY new MAC address from being added to the network and force a mac address to a specific port. But the most interesting feature is this - a frame sent to a specific mac address only shows up at the port that mac address is attached to. All other ports get the header with the data field blank! (filled with 1s & 0s) - you can't capture other people's traffic! only your own! (they're doing the filtering during the normal buffer copy in the repeater - so there is no impact on delay - it's within 10baseT spec). So now I've got an ethernet that acts sorta' like SNA. Users can only attach to a specific port and only traffic destined for that port appears. -- John Robert Breeden, jbreeden@netcom.com, apple!netcom!jbreeden, ATTMAIL:!jbreeden ------------------------------------------------------------------- "The nice thing about standards is that you have so many to choose from. If you don't like any of them, you just wait for next year's model."