Custom DHCP Option

I have the following problem at the moment:

I want to set the DHCP option Code: 078

So my question which type I have to choose that I can use a IP Adress in the value?


  • edited March 2020

    IP Address(es) - which is at the bottom of my Type list in WSM Policy Manager

  • @Bruce_Briggs which list do you mean?

  • Type list

  • Ok I got it

  • Is it even possible to give the option 78?

  • edited March 2020

    @Daniel_P30 said:
    Is it even possible to give the option 78?

    Yes, by using the Custom Option radio button when adding a DHCP Option.

    Gregg Hill

  • @Greggmh123 thanks for the answer. Maybe do you have expirience with extreme aps. Because my problem is that the Aps dont get the IP from the Controller over the DHCP.

  • Daniel,

    I had no idea what Option 78 was until just now! I just commented to explain that any number can be used as an option via Custom Options.

    Can those access points find the controller via DNS? I haven't even heard of that brand before.

    I use UniFi access points, and when a new one starts up, it looks for "unifi" to get the controller's address. In a network with a Windows DNS server on site, I set up a "unifi" CNAME, and that CNAME points to the public FQDN of my controller, let's call it "". The AP starts up, looks for "unifi" which it finds as a CNAME on the LAN DNS server, it gets pointed to my UniFi controller, and it shows up in the controller (if I remember to add the client's WAN IP to my allowed inbound alias to the controller!). I can factory reset an AP at one of those clients and it will phone home to my controller.

    In the absence of a local DNS server, the UniFi APs can find the controller's IP address via DHCP Option 43 (I think it's 43), BUT that does me no good because my own WAN IP is dynamic. That's why I always set up my APs to get the controller's FQDN, even locally, and my internal DNS server points "" to the VLAN IP of the controller. I can set up an AP here, it gets connected to "" via local DNS, and then I can take it offsite and it still finds the controller over the Internet.


    Gregg Hill

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