Date: Wed, 21 Jul 1999 10:14:51 -0700 (PDT) From: Vincent Poy <vince@venus.GAIANET.NET> To: Wes Peters <wes@softweyr.com> Cc: Matthew Dillon <dillon@apollo.backplane.com>, Jaye Mathisen <mrcpu@internetcds.com>, Modred <modred@ns1.antisocial.net>, sthaug@nethelp.no, leifn@neland.dk, freebsd-hackers@FreeBSD.ORG Subject: Re: poor ethernet performance? Message-ID: <Pine.BSF.4.05.9907211013530.331-100000@venus.GAIANET.NET> In-Reply-To: <3795DD5E.2F71FBFB@softweyr.com>
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On Wed, 21 Jul 1999, Wes Peters wrote: > Matthew Dillon wrote: > > > > :Perhaps I'm missing something obvious, but since switches forward packets > > :selectively per port, I would think it would be hard to sniff packets on > > :any port, w/o administrative access to the switch to tell it to mirror > > :data to a different port. > > : > > :ie, if I'm plugged into port 1, I can't see traffic on a switch on port 2 > > :except for broadcast traffic... > > > > The switch routes traffic based on its ARP cache. While you cannot > > easily monitor another port's traffic, you can take over its MAC address > > and steal its traffic. > > Unmanaged layer 2 switches do that, but the "intelligent" layer 3 switches > certainly don't. Layer 3 switches can be configured to consider 2 physically > adjacent ports to be on completely different networks; they will not even > share broadcast traffic. If you shop carefully, you can even buy switches > where you can configure VLANs based on user authentication, any given > physical port can join a VLAN based on a user login program rather than > port number or MAC or IP address. Speaking about Layer 2 and layer 3. Does the Cisco Catalyst 2924XL and the HP ProCurve 2424M and 4000M switches fall under Layer 3 or just layer 2? Cheers, Vince - vince@MCESTATE.COM - vince@GAIANET.NET ________ __ ____ Unix Networking Operations - FreeBSD-Real Unix for Free / / / / | / |[__ ] GaiaNet Corporation - M & C Estate / / / / | / | __] ] Beverly Hills, California USA 90210 / / / / / |/ / | __] ] HongKong Stars/Gravis UltraSound Mailing Lists Admin /_/_/_/_/|___/|_|[____] To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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