Re: Conversion canonical to non-canonical

From: Chris Larson (clarson52@xxxxxxxxxxx)
Date: Sun Apr 28 2002 - 22:08:09 GMT-3


   
If by chance you want it in notepad so it comes out right e-mail me direct
and I waill give you the attatchment. I think there is a good document on
CCO that basically walks thru the same procedure.

----- Original Message -----
From: "Chris Larson" <clarson52@comcast.net>
To: "Chris Larson" <clarson52@comcast.net>; "Babacar Diop"
<babacard2000@yahoo.com>; <fningham@att.net>
Cc: "cciegroup" <ccielab@groupstudy.com>
Sent: Sunday, April 28, 2002 9:02 PM
Subject: Re: Conversion canonical to non-canonical

> I guess this did not come out right so you can't really follow it. Sorry.
>
> ----- Original Message -----
> From: "Chris Larson" <clarson52@comcast.net>
> To: "Babacar Diop" <babacard2000@yahoo.com>; <fningham@att.net>
> Cc: "cciegroup" <ccielab@groupstudy.com>
> Sent: Sunday, April 28, 2002 6:26 PM
> Subject: Re: Conversion canonical to non-canonical
>
>
> > If it is ethernet, and you are building filters for dlsw always convert.
> >
> >
> > As for converting, you do not need to memorize the numbers if you
convert
> to
> > binary flip then swap.
> > I only know 1 way to convert and it is probably the same as everyone
else
> > except I find it eaiser to flip the binary reference then trying to flip
> the
> > binary number. It just seems to be quicker and I can do it without
> thinking
> > too much. A hex number is represented by a nibble or half a byte in
> binary.
> > Take 2 hex digits at a time, convert them to binary, flip the binary
> number
> > (or reference ) and reverse their places.
> >
> > Canonical: = 04 5a 49 88 d7
> >
> > Take the first 2 numbers and convert to binary
> >
> > binary reference 8421
> > 8421
> > 0 in binary = 0000 4 in binary =
> 0100
> >
> > Now we have the binary number we flip it. I find it easier to flip the
> > reference rather then flipping the binary number. The way I was taught
of
> > course was to flip the binary number (not the reference as shown), but
> this
> > seems to be a waste of time, and for me is a little more difficult to do
> in
> > my head then just reversing the reference. Just count the reference
> > backwards.
> >
> > 1248 1248
> > 0 flipped = 0000 4 flipped = 0100 or 2
> >
> > of course zero is zero in hex and 4 is 2 in hex. All we have to do is
> swap
> > places from the two numbers we took. Just swap the first and second
> numbers
> > so the non canonical equivelant of this excerise is
> >
> > 20
> >
> > moving to the next group of two hex numbers. 5A
> >
> > 8421 8421
> > 1248 1248
> > 5 = 0101 a= 1010 flip 'em
> > 0101 = a hex 1010 = 5 hex
> >
> > swap places 5a we now have 205a.
> >
> > 8421 8421
1248
> > 1248
> > 4 = 0100 9 = 1001 flip 0100 =2
> > 1001 = 9. swap 92 now we have 205a92. 8 is relatively easy
> > especially since there are 2 in a row. 8 flipped of course is 1. so 11.
we
> > have 205a9211, and lastly
> >
> > 8421 8421
> 1248
> > 1248
> > d= 1101 7 = 0111 flip 1101
=b
> > 0111 = e swap eb
> >
> > 205a9211eb
> >
> >
> >
> >
> >
> > ----- Original Message -----
> > From: "Babacar Diop" <babacard2000@yahoo.com>
> > To: <fningham@att.net>
> > Cc: "cciegroup" <ccielab@groupstudy.com>
> > Sent: Sunday, April 28, 2002 3:56 PM
> > Subject: Re: Conversion canonical to non-canonical
> >
> >
> > > Does anyone has a better explanation for this? I would
> > > really appreciate it. Also, is there an easy way to do
> > > the conversion or does one have to memorize how to
> > > convert every single digit/character?
> > >
> > > Thanks
> > >
> > >
> > > --- fningham@att.net wrote:
> > > > DLSW uses only non-canonical addresses so you would
> > > > need to convert whenever you have an Ethernet
> > > > address
> > > > to use in a DLSW statement. This could be in a
> > > > icanreach statement, or in a MAC filter access-list.
> > > >
> > > > HTH, Fred
> > > > > Group,
> > > > >
> > > > > When do you need to convert from canonical to
> > > > > non-canonical in DLSw. Anyone as a doc on when and
> > > > how
> > > > > to do it?
> > > > >
> > > > > Thanks
> > > > >



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