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DLSW Strange MAC Addresses *HELP*

Hello all,

I have two PCs connected over a DLSW dynamic peer (or any old peer). The MAC address of the IBM-PC is 00-01-03-86-04-34

(but in the DLSW reachability command it is reported as 0080.c061.202c) and the compaq-laptop MAC address is 00-10-a4-00-65-c1 (again, the DLSW reachability command reports it as 0008.2500.a683)

Can anyone explain why this is? The DLSW peers are peering off a loopback address off each router but loopbacks do not have MACs do they? If so, I cant find these two MAC addresses that the DLSW command is reporting.

Many thx indeed.

Ken

rtr3>sh dlsw rea

DLSw Local MAC address reachability cache list

Mac Addr status Loc. port rif

0080.c061.202c FOUND LOCAL TBridge-0DD --no rif--

DLSw Remote MAC address reachability cache list

Mac Addr status Loc. peer

0008.2500.a683 FOUND REMOTE 30.1.3.1(2065) max-lf(1500)

DLSw Local NetBIOS Name reachability cache list

NetBIOS Name status Loc. port rif

IBM-LAPTOP FOUND LOCAL TBridge-0DD --no rif--

DLSw Remote NetBIOS Name reachability cache list

NetBIOS Name status Loc. peer

COMPAQ-LAPTOP FOUND REMOTE 30.1.3.1(2065) max-lf(1500)

rtr3>

1 REPLY
Silver

Re: DLSW Strange MAC Addresses *HELP*

Hi Ken,

this is simple to explain:

entries in show dlsw reach appear in non-canonical format as opposed to canonical format as on Ethernet or in the output of show bridge.

0080.c061.202c is the non-canonical format of 00-01-03-86-04-34

0008.2500.a683 is the non-canonical format of 00-10-a4-00-65-c1

So, ethernet attached devices appear with their MAC addresses translated while Token-Ring attached devices don't.

Cisco has a Bitswapping Tool (available to registered users) to translate between canonical and non-canonical MAC addresses:

http://www.cisco.com/cgi-bin/Support/Bitswap/bitswap.pl

Hope this helps

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