Re: Canonical/Non-Canonical conversion

From: George Harizanov (georgehar@xxxxxxxxxxx)
Date: Mon Mar 20 2000 - 04:12:45 GMT-3


   
   Thanks Ben..
   
   I hope you have a good tango partner :)
   
   Regards
   
   ----- Original Message -----
   
   From: Ben_J_Durand@tivoli.com
   
   To: Derek Small (Fuse)
   
   Cc: George Harizanov ; ccielab@groupstudy.com
   
   Sent: Sunday, March 19, 2000 8:48 PM
   
   Subject: Re: Canonical/Non-Canonical conversion
   
     Derek,
     You are correct. It does need to go through the
     cannonical->noncannonical
     conversion for the manual ICANREACH when dealing with ethernet
     hosts. The quick
     and dirty way to check is to do a "show bridge" and "show dlsw
     reachability"
     while having an ethernet PC on an ethernet bridge-group interface.
     For example:
     "show bridge" show MAC address 0080.c71e.65df on e 0
     "show dlsw reachability" shows MAC address 0001.e378.a6fb as a
     local MAC
     address. Same machine, just with the MAC address having gone
     through the
     conversion.
     George, the easy way to convert using the hex form: Go byte by
     byte and flip
     the bits the way Derek told you:
     Hex Binary Flip! Binary Hex
     00 -> 00000000 00000000 00
     80 -> 10000000 00000001 01
     . .
     C7 -> 11000111 11100011 E3
     1E -> 00011110 01111000 F8
     . .
     A6 -> 10100110 01100101 65
     FB -> 11111011 11011111 DF
     So 0080.C71E.A6FB, the actual MAC address of the ethernet card,
     appears as
     0001.E3F8.65DF in DLSW. This is also how it would appear to a
     token-ring
     interface if you were using source-route translational bridging.
     Hope this helps.
     - Ben
     9 days before the tango.
     "Derek Small (Fuse)" <dwsmall@fatkid.com> on 03/19/2000 02:53:00 PM
     Please respond to "Derek Small (Fuse)" <dwsmall@fatkid.com>
     To: "George Harizanov" <georgehar@mindspring.com>,
     ccielab@groupstudy.com
     cc: (bcc: Ben J Durand/Tivoli Systems)
     Subject: Re: Canonical/Non-Canonical conversion
     I've never found one either but the process is very simple. Just
     reverse the
     direction you read each byte. Hence 10110001 in canonical (used in
     Ethernet)
     becomes 10001101 in non-canonical (Used in Token Ring and FDDI)
     It's a little
     harder to do directly in HEX because you work with four bits at a
     time instead
     of 8, so 10110001 which in HEX is B1, becomes 8D. You probably
     won't find
     anything on Cisco's site, because the process is pretty strait
     forward and
     doesn't require enough effort for one of Cisco's engineers to write
     up. The
     only hard part about the conversion is knowing which version you
     are looking at.
     While we are on the subject. Someone recently posted that DLSW
     ICANREACH
     addresses are always entered in non-canonical format, even if the
     host specified
     is Ethernet attached. This is the first place I have heard this
     (at least that
     I recall). I only saw the one post on this. Can a few of you
     confirm this. I
     don't have many DLSW references, and nothing I have indicates this
     fact. (It
     makes a lot of sense though.)
     Thanks
     Derek Small
     dwsmall@fatkid.com
       ----- Original Message -----
       From: George Harizanov
       To: ccielab@groupstudy.com
       Sent: Sunday, March 19, 2000 9:18 PM
       Subject: Canonical/Non-Canonical conversion
       Hi everybody..
       I gave up looking for a reference on the CCO about
     Canonical/Non-Canonical
     conversion.
       Does anybody know if such a link exist ?
       Thanks in advance
       George



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