From: Andrew B. Caslow (abcaslow@netmasterclass.net)
Date: Tue Jun 15 2004 - 18:17:29 GMT-3
Peng,
As already mentioned by others, DLSw+ processes all MAC addresses in
non-canonical format. Therefore, if you wanted to specify an Ethernet
originated frame with any DLSw+ command such as an "icanreach" command or a
dmac-output-list referenced in a remote-peer statement, you need to convert
the canonical Ethernet address into a non-canonical format.
However, if you wanted to filter an Ethernet frame by MAC address at the
very edge of your DLSw+ configuration, this would be at the Ethernet
interface level with interface configuration commands such as:
R1(config-if)#bridge-group 1 input-address-list ?
<700-799> Ethernet address access list
R1(config-if)#bridge-group 1 output-address-list
Then you would not convert the Ethernet MAC address into a non-canonical
format. These commands operate with the transparent bridging process. While
the Ethernet frames are being processed by the transparent bridging process,
their address formats are still interpreted in a canonical format. It is
when the Ethernet frames are transferred to the DLSw+ process that they are
interpreted in a non-canonical format.
To better understand this, compare an Ethernet MAC address that is processed
in a DLSw+ configuration with the following two show commands generated on
the same router:
************************
R1#sh bridge
Total of 300 station blocks, 299 free
Codes: P - permanent, S - self
Bridge Group 1:
Address Action Interface Age RX count TX count
0000.861f.6892 forward Ethernet0 0 24 0
************************
R1#sh dlsw reach
DLSw Local MAC address reachability cache list
Mac Addr status Loc. port rif
0000.61f8.1649 FOUND LOCAL TBridge-001 --no rif--
************************
Again, these two commands should be performed on the same router. The router
is an edge DLSw+ device connecting an Ethernet segment configured with
transparent bridging to a locally configured DLSw+ process.
With the "show bridge command", the Ethernet MAC address is still
represented in a canonical format. This is because the MAC address is still
being processed by the router's transparent bridging module. With the "show
dlsw reachability" command, the Ethernet MAC address has been converted into
a non-canonical format. At this point, the MAC address is now being
processed by the router's DLSw+ module.
For more details on DLSw+ filtering, check out the 13 page NetMasterClass
Tech-Note at http://www.netmasterclass.net/site/lib.php
The paper is titled "DLSw Filtering". It is loaded with examples and
detailed explanations.
HTH,
-Bruce Caslow CCIE #3139
NetMasterClass, LLC
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Nigel.Johnson@barclayscapital.com
Sent: Tuesday, June 15, 2004 2:55 AM
To: cccie71@yahoo.com; zpnist@yahoo.com; ccielab@groupstudy.com
Subject: RE: When Mac conversion is required?
I would convert both too. DLSW always uses non-canonical addresses.
Nigel
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Tom
Rogers
Sent: 15 June 2004 07:00
To: Peng Zheng; ccielab@groupstudy.com
Subject: Re: When Mac conversion is required?
I would convert in both if the resource is on Ethernet.
Peng Zheng <zpnist@yahoo.com> wrote:Hi,
For dlsw config with only Ethernet, when should I
convert the cannonical to non-cannonical address?
Do I need to convert in
dlsw icanreach max-address
and
dmac-output-list?
Thanks.
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