05-10-2010 10:13 AM - edited 03-01-2019 09:39 AM
When I create pools of wwn and macs for a service profile template, is there a block of addresses that start with an OUI that are specific to UCS? In this guide: http://www.ciscosystems.sc/en/US/products/ps10281/products_configuration_example09186a0080af7515.shtml, I can see the a tip in the window of this picture: http://www.cisco.com/image/gif/paws/110297/create-sp-ucsblade-11.gif that specifies using a prefix of 20:00:00:25:B5:xx:xx:xx will ensure uniquiness in the WWN names but when I'm at the same screen on our UCS, I don't see this tip. The same goes for the MACs, is there a block with certain values I should start with? The MAC section of the guide shows 02:25:B5:00:00:00 in the configuration window: http://www.cisco.com/image/gif/paws/110297/create-sp-ucsblade-09.gif but is this unique to UCS?
Thanks.
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05-12-2010 12:03 PM
For MACs Cisco has registered the OUI 00:25:b5 the last three octets are up to you. You can either make up some arbitrary numbers or you can put some logic behind it. Here is what I recommend for MACs.
For the WWNNs and WWPNs you will want three pools; one for the node WWN and two for the port (vHBA) WWN.
Same concept here for the WWNNs use something like 20:11:00:25:b5:00:00:00 for site 1 cluster 1 and 20:12:00:25:B5:00:00:00 for site 1 cluster 2.
For the WWPN pools do one for Fabric A and one for Fabric B like this
By creating MAC and WWPN pools for each Fabric you can easily identify which Fabric a MAC or WWN is coming from when looking the MAC table on a switch or when zoning you can easily pick out WWNs. Could be useful when troubleshooting as well.
05-12-2010 12:03 PM
For MACs Cisco has registered the OUI 00:25:b5 the last three octets are up to you. You can either make up some arbitrary numbers or you can put some logic behind it. Here is what I recommend for MACs.
For the WWNNs and WWPNs you will want three pools; one for the node WWN and two for the port (vHBA) WWN.
Same concept here for the WWNNs use something like 20:11:00:25:b5:00:00:00 for site 1 cluster 1 and 20:12:00:25:B5:00:00:00 for site 1 cluster 2.
For the WWPN pools do one for Fabric A and one for Fabric B like this
By creating MAC and WWPN pools for each Fabric you can easily identify which Fabric a MAC or WWN is coming from when looking the MAC table on a switch or when zoning you can easily pick out WWNs. Could be useful when troubleshooting as well.
05-26-2010 07:54 AM
Thanks for the detailed response Jeremy!
02-12-2014 11:34 AM
The answer given does not really answer the question:
"...is there a block of addresses that start with an OUI that are specific to UCS?"
In other words, is the Cisco-owned block, 00:25:B5, used exclusively by UCS products? When using these addresses in UCS, does the customer need to worry that adjacent (non-UCS) switches might use the same Cisco-owned OUI, or is this OUI reserved exclusively for UCS?
02-12-2014 08:19 PM
Hi and welcome to the community,
The answer is here in the same configuration guide...
"A MAC pool is a collection of network identities, or MAC addresses, that are unique in their layer 2 environment and are available to be assigned to vNICs on a server."
Bottom line.. 00:25:b5 is owned by Cisco, but the MAC addresses are going to be unique for that layer 2 domain.
Rate ALL helpful answers.
-Kenny
02-13-2014 07:03 AM
Hi Kenny,
Thanks for responding, but this still does not answer the question. The question is:
Is the 00:25:b5 range reserved exclusively for UCS, or is there a chance that some non-UCS devices may have addresses in that range? This is important to know. If this range is UCS-only, then a customer can safely use this range for their VNICs, and not worry about having a MAC conflict with adjacent Cisco switches.
The page that you linked me to in the configuration guide does have any information about this topic, although that is where one would expect this information to be found. (I have been told, and have seen it somewhere in print in the past, that this range is UCS-only, but now I am trying to verify it, and have not found the MAC address rules in the configuration guide.)
Thank you.
02-13-2014 07:50 AM
....Is the 00:25:b5 range reserved exclusively for UCS, or is there a chance that some non-UCS devices may have addresses in that range?....
NO ! customer is responsible to configure unique MAC range for every UCS domain, very important if you have >1 UCS domain on same L2 domain.
02-13-2014 08:29 AM
Thank you wdey. Of course that is the case. But again, that is not the question that is being asked. The question is this:
Does Cisco use the 00:25:b5 range for any non-UCS products, or is this range specifically reserved as UCS-only? That was the orginal poster's question, and I also repeated the question in my above posts.
02-13-2014 08:32 AM
00:25:b5 prefix is used by Cisco, in general, not dedicated to UCS !
02-13-2014 09:56 AM
That OUI is for Cisco in general, the rest is just too much space to dedicate it only to UCS... We expect a good amount of servers to sold but it is just to much considering that, as explained in the "answer" for this post, you can make some variations to give them some sort of sense.
-Kenny
02-13-2014 11:35 AM
Thank you wdey and Kenny, that answers the question.
So, if a customer assigns MAC addresses to VNICs, using the 00:25:B5 range, there is a chance that there could be a MAC address conflict, if an adjacent Cisco switch in the same L2 domain has a burnt-in MAC in that same range?
02-13-2014 11:39 AM
Correct
-Kenny
02-13-2014 11:45 AM
Thank you for clarifying that.
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