Single deployment DHCP option 43 config in Infoblox

Use this guide to configure you InfoBlox to provide the Wireless LAN Controller address via DHCP option 43 to ANY device. If you need to provide the option only to Cisco APs or different option per AP type – This is not the guide!


  • Select DHCP–>Networks–>Select your subnet (alternatively can do this per DHCP Scope)
  • Click “Modify” and under IPv4 DHCP Options click Plus(+)
  • Select “vendor-ecapsulated-options (43) string”

For your value, you’ll need to enter the IP in HEX preceeded by the number of WLC’s you want to include in your DHCPOFFER (also in HEX).
That last one warrants some further explanation.

First convert your IP address to HEX. Here’s a handy site to do that for you:
Precede that HEX value with F1:04 for a single WLC, f1:08 for two WLC’s, f1:12 for 3 WLC’s etc. etc. (in my example I’m using a single WLC).

Your final IPv4 DHCP Options (per subnet) should look something like this:

Note the last DHCP Option:, in HEX is 0AFC0114 and that is preceded with F1:04.

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