Configure DHCP Option 78 in Windows Server With 2 Controllers

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We are using Windows for DHCP and have two controllers. We are in the middle of testing for a re-addressing project and can only get APs local to the 1st controller, who's address is handed out with Option 78, to work when changing subnets. I can add the two controllers to each AP, or make the APs local to the first controller before flipping them, but was hoping to do it a little more gracefully than that. I haven't found much good documentation on Option 78 in Windows. Is it possible to add a 2nd address using Option 78  in Windows Server?
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Rick Lester

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Posted 8 months ago

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Craig Guilmette, Employee

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Craig Guilmette, Employee

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just type in the second set of IP's after the 1st one, you do not add another 1 or a 2 that Microsoft puts there by default. 
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Craig Guilmette, Employee

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I prefer using DNS resolution, you simple add 2 A records to your DNS server for the same name of controller and resolve it to 2 separate IP's of the controllers and when our AP's get the IP from dhcp as well as the FQDN and the DNS server the next thing the ap's do is say hey DNS server who is controller and append your FQDN and the DNS server answers with both IP addresses of the controllers and if you set your access control on both controllers to allow ONLY approved the AP's will be pending on both and you can accept them on which ever controller you wish :) 
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Rick Lester

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Thanks for your quick comments. That  was just what I was looking for and appears to work as expected. I saw that article, but I obviously didn't read it carefully enough, especially step 11. The DNS option looks good too, but Option 78 was already set up by another admin, just not completely.

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Doug Hyde, Technical Support Manager

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Thanks for the followup Rick, glad it's all working for you.