Good afternoon colleagues a query I need to open port 53 udp on the server debian 8. my question is the following my server has no firewall installed but at the time of scanning all ports I see that it is open tcp 53 and others. but port 53 udp n. my query is that I need to install a firewall to be able to open that udp port or I can open that port without needing a firewall
I hope for your good comments, thank you very much.