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3502e not seeing option 43


We're attempting to bring up 68 3502e APs in a facility that already has nearly 300 3502i APs in production.  For some reason, all E models are unable to discover WLCs from option 43.  Example log:

%CAPWAP-3-DHCP_RENEW: Could not discover WLC using DHCP IP. Renewing DHCP IP.

An unconfigured 3502i was connected to the same port a 3502e was on and it successfully discovered and joined a controller:

%CAPWAP-5-DHCP_OPTION_43: Controller address obtained through DHCP"

This rules out misconfiguration on the DHCP server.  Has anyone else seen this type of behavior before?  Any suggestions for further troubleshooting?

2 Replies 2

Lovleen Arora


can you try the below link and see it that helps you.


Also note the order in which an AP links to a wlc.


1. Broadcast

2. DNS


 so for example if it si matching the dns, it won't go looking for option-43.



We've found the problem.  For the edification of anyone else who may encounter this, here's the explanation.  Starting with this:


"Option 60 is included in the initial DHCP discover message that a DHCP client broadcasts in search of an IP address. Option 60 is used by DHCP clients (LAPs in this case) in order to identify itself to the DHCP server.

If the access point is ordered with the Service Provider option (AIR-OPT60-DHCP selected), the VCI string for that access point is different than those listed above. The VCI string includes the ServiceProvider option. For example, a 1260 with this option returns this VCI string: Cisco AP c1260-ServiceProvider.

If the Cisco AP runs or above (12.4 (23c) JA2 or above) and if a bootloader environmental variable (env_vars) namedDHCP_OPTION_60 exists in flash, the value is appended to the VCI. If you order a Cisco AP with the Service Provider option, it will (by default) include the -ServiceProvider suffix; however, you can include other values into DHCP_OPTION_60 as well."


Whoever ordered these APs apparently selected the Service Provider option, so the "Cisco AP c3500" VCI string wasn't adequate.  We created a new VCI with "-ServiceProvider" appended, and that did the trick.

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