18.04 – isc-dhcp-server and systemd-networkd

I think systemd-NetworkD Support for DHCPServer is limited based on https://www.freedesktop.org/software/systemd/man/systemd.network.html#%5BDHCPServer%5D%20Section%20Options

However, you are probably better off with it ISC DHCP server If you need to tune multiple DHCP subnets simultaneously or provide advanced DHCP options and the like.

I have an LXD network that uses an 18.04 container that provides DHCP to all other containers on this subnet. It seems to work systemd-NetworkD and netplan DHCP clients.

Note that in either In any case, the DHCP server should have a static IP address outside the DHCP pool. This way, the server behaves consistently.

Can the isc-dhcp-server update bind run on a non-standard port?

I do the following on the same server: pi-hole, bind9, isc-dhcp-server, and cloudflared (for DNS over HTTPS). The order goes like this:

Hole: 53 -> Bind9: 54 -> Cloud: 5353

I'm now installing isc-dhcp-server as my authoritative DHCP server because my Ubiquity router can not really manage hostnames well and does not update DNS (uses a host file). I used to set up DDNS in the past, but now that I've run Pi-Hole on the standard DNS port (53), I'm not sure if dynamic updates are working properly.

I tried to look at the manual for ISC-dhcp-server, but all I can find for the primary DNS is an IP, not an option for the port. My question is, how does the isc-dhcp-server update bind? I know it uses a TSIG key for authentication, but does it still work if Bind is running on a different port?

Many Thanks!