Option 43 On Catalyst 3560G

Unanswered Question
Oct 10th, 2007

Does anyone know if DHCP Option 43 is available on the Catalyst 3560G. I have 3 controllers and I want to make my 1130 series APs join the appropriate controller. I believe DNS is currently being used which is pushing all my APs to the same controller.

Does anyone of instructions on how to configue option 43 on the 3560?

Thanks for any help,

I have this problem too.
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john.preves Wed, 10/10/2007 - 18:38

option 43 is not configured on the switch just the DHCP scope you will assign whatever vlan will be on the switch. Option 43 will push all your AP's to the same controller as well.

Unless I'm wrong of course, but I have been manually moving AP's around to the correct controller since I only have one master.

I'll stay tuned to this one as now I'm curious

scottwilliamson Thu, 10/18/2007 - 07:28

Hi Mark,

One of my 3560s is accepting the commands for a DHCP pool with option 43.

Whether it works or not is another matter though as I'm not in a position to test it.



Scott Fella Thu, 10/25/2007 - 06:59

Scott is right, they will still join on controller. To move the ap's to the correct controller, you either have to manually set the primary, secondary and or tertiary on each controller or if you have ECS, you can push out a template to specifice ap's.

The hard way using option 43 is that you stage certain ap's witha specific controller using option 43 then change the ip in the option 43 to the other controller and boot up the ap's for that. etc....

jeremy.porter Thu, 10/25/2007 - 11:47

Within DHCP option 43 you can add any number of controller IP addresses. I have not tested if this works or not, but the premise is if the first controller in the list is not available it will use the next.

To configure IOS DHCP server with option 43:


Then go to the IOS section.

Once the AP has connected you will want to use WCS or manually configure the primary/secondary/tertiary controller on each AP. You could get away with not doing this (and allowing DHCP option to provide failover options) but failover time would increase, the AP would most likely need to reload to find another controller (again, untested).


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