From: Ben_J_Durand@xxxxxxxxxx
Date: Sun Mar 19 2000 - 17:48:03 GMT-3
Derek,
You are correct. It does need to go through the cannonical->noncannonical
conversion for the manual ICANREACH when dealing with ethernet hosts. The quic
k
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 specifie
d
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
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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