what do you mean by open connection?
Keep in mind that /30 means only 2 bits left for (host)addressing which equals 4 ip addresses in that net segment. The first and last are alrdy "reserved" for net address itself and broadcast address. So two ip addresses left, one will be assigned to the gateway (aka. physical interface on your router) tho and finally the last one will be your host ip address.
e.g. 192.168.1.0/30
Net address: 192.168.1.0
Gateway: 192.168.1.1 (ofc you can decide which one is gateway or host)
Host1: 192.168.1.2
Broadcast: 192.168.1.3
next net is 192.168.1.4/30 (if you keep /30)
....
Basically if you need to make sure that all of your local networks have a gateway. Eihter setup your router to provide those or your firewall if it supports layer 3/4 switching. Only one device should do the job. I know you did it one or two times, but check it a third time. It still smells like a conceptional/network issue ;)
Good Luck!
