Windows service I'm writing can't talk on

Question

I'm writing a Windows service that needs to speak to other machines on the network (udp). The service will eventually be running in a closed network environment (embedded systems for robotics talking over ethernet), so security isn't really what we're concerned about. For many reasons, at the moment it's easier to run with Windows Firewall turned off. File sharing/pinging/dev tools etc just work across sub nets with it off, and we don't have to screw around with firewall exceptions for all of that. Especially since most of it won't be needed in the final environment, it's just for our convenience now.

HOWEVER, when I turn off the firewall, my service is no longer receiving packets. If the firewall is on (with an exception added for my service), my service gets packets fine (but other things can't due to the firewall). This seems a little insane to me.

I've read that this might have something to do with Windows Service Hardening. I've started digging into that, but it seems to be a pretty expansive topic. I'm not sure which parts I need to be worried about, and I'd be just as happy if I could just turn it off.

If somebody could please explain to me the best way to go about "making it work" with the firewall disabled (I don't care if it's insecure), that would be much appreciated. I never thought I'd be missing IPTABLES.