Unifi: DHCP domain-search on the UDM-SE
One of the little things missing from OpenWRT (I can’t even remember setting it up TBH, I think it worked out the box) since switching back to Unifi is the lack of the
domain-search option on the DHCP server.
You see, I have several domains at home for the different VLANs: stuff on the main network is on say,
fwaggle.org, stuff on the home one is on
home.fwaggle.org, stuff in the office on
office.fwaggle.org, and so on. But if for example I want to connect to the machine named
desktop, if I’m not on the same VLAN as it, I must type the entire FQDN. Who has time for that?!
domain-search to the rescue, which… is not natively supported by the UDM-SE. I can specify DHCP options manually though, so I looked it up and it’s option 119. A text string didn’t feel right, because it should be an array, so I used hex array instead. I found a script that’s supposed to convert it for you, but when I tried this I got an error “there was an issue applying your configuration, please restore from a backup” (which sounds way worse than it actually is!).
I later learned that you can literally just use option
119, the type
text, and a comma-separated list of domains. That’s it. So if I set the value as
office.fwaggle.org,home.fwaggle.org,fwaggle.org on my office domain, and
home.fwaggle.org,fwaggle.org on the home one, and so on, it just goddamn works.
So that’s one more thing ticked off the list of annoyances.