From: John Elias (jelias_@xxxxxxxxxxx)
Date: Sun Jul 01 2001 - 21:09:53 GMT-3
Rick,
Thanks for the explaination, I understand it now.
John
>From: Rick Burts <burts@mentortech.com>
>To: John Elias <jelias_@hotmail.com>
>CC: signal@shreve.net, ccielab@groupstudy.com
>Subject: Re: bitswap-layer3-addresses
>Date: Sun, 1 Jul 2001 07:48:20 -0400 (EDT)
>
>John
>
>The original question had to do with the command bitswap-layer3-address.
>The function of that command is to go into the layer 3 payload of certain
>packets (where the MAC is part of the payload) and perform the canonical/
>non canonical bitswap). If an Ethernet station sends a canonical MAC in
>a reply to a Token Ring station as part of the payload (think IPX GNS for
>example) and the non-canonical Token Ring station uses that MAC as the
>destination address without bitswaping, the frame will not contain the
>correct address after it goes through the bridge.
>
>Rick
>
>Rick Burts, CCSI CCIE 4615 burts@mentortech.com
>Mentor Technologies 240-568-6500 ext 6652
>133 National Business Parkway 240-568-6515 fax
>Annapolis Junction, Md 20701
>
>Chesapeake Network Solutions has now become Mentor Technologies.
>Mentor Technologies is a certified Cisco Training Partner and also
>a Cisco Professional Services partner.
>We offer most of the Cisco training courses.
>We also offer training in Checkpoint Firewall software and
>Fore Systems (now Marconi) and MicroMuse.
>We also provide network consulting services including
>design, management, and problem solving.
>We have 21 CCIEs on our staff.
>We offer the breakthrough VLAB remote access technology for
>access to practice configuration on real equipment.
>
>On Sat, 30 Jun 2001, John Elias wrote:
>
> > Rick,
> > Everything you are saying is true, but I thought that the
> > canonical/non-canonical bit ordering was only for the 2nd layer(MAC).
>How
> > is it involved with the 3rd layer(IP/IPX/etc.)?
> >
> > John
> >
> >
> > >From: Rick Burts <burts@mentortech.com>
> > >Reply-To: Rick Burts <burts@mentortech.com>
> > >To: Brian <signal@shreve.net>
> > >CC: ccielab@groupstudy.com
> > >Subject: Re: bitswap-layer3-addresses
> > >Date: Sat, 30 Jun 2001 11:56:08 -0400 (EDT)
> > >
> > >There have been a couple answers to this but I would like to take a
> > >slightly different approach to this. bitswap-layer3-address is
> > >needed when transparent bridging is used between Ethernet and Token
> > >Ring. (The reason it is needed is to process when a MAC address is
> > >included in the payload of the frame as well as in the data link header
> > >and this will compensate for the canonical/non-canonical bit ordering.)
> > >It is obvious that SRT is doing transparent bridging and needs bitswap.
> > >It may not be quite as obvious (but it is true) that SR/TLB is also
> > >doing transparent bridging and may need bitswap.
> > >
> > >Rick
> > >
> > >Rick Burts, CCSI CCIE 4615 burts@mentortech.com
> > >Mentor Technologies 240-568-6500 ext 6652
> > >133 National Business Parkway 240-568-6515 fax
> > >Annapolis Junction, Md 20701
> > >
> > >Chesapeake Network Solutions has now become Mentor Technologies.
> > >Mentor Technologies is a certified Cisco Training Partner and also
> > >a Cisco Professional Services partner.
> > >We offer most of the Cisco training courses.
> > >We also offer training in Checkpoint Firewall software and
> > >Fore Systems (now Marconi) and MicroMuse.
> > >We also provide network consulting services including
> > >design, management, and problem solving.
> > >We have 21 CCIEs on our staff.
> > >We offer the breakthrough VLAB remote access technology for
> > >access to practice configuration on real equipment.
> > >
> > >On Tue, 26 Jun 2001, Brian wrote:
> > >
> > > > A few questions about the "bitswap-layer3-addresses" directive.
> > > >
> > > > I am just trying to nail down when this command is really
> > > > required. I know that if I have a token ring interface
> > > > and a ethernet interface on a router, and I am doing SRT
> > > > between them, then I need it like so:
> > > >
> > > >
> > > > int token0
> > > > bridge-group 1
> > > >
> > > > int ethernet0
> > > > bridge group 1
> > > >
> > > > bridge 1 protocol ieee
> > > > bridge 1 bitswap-layer3-addresses
> > > >
> > > >
> > > > But the documentation at cisco.com mentions SR/TB as well.
> > > >
> > > > I am confused as to when you would use it with SR/TB, can
> > > > someone show a quick example of where you would want to use
> > > > it with something other than SRT?
> > > >
> > > > Brian
> > > >
> > > > -----------------------------------------------
> > > > Brian Feeny e:signal@shreve.net
> > > > CCNP+Voice/ATM/Security p:318.222.2638x109
> > > > CCDP f:318.221.6612
> > > > Network Administrator
> > > > ShreveNet Inc. (ASN 11881)
> > > > **Please read:http://www.groupstudy.com/list/posting.html
> > >**Please read:http://www.groupstudy.com/list/posting.html
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