Portqry Udp [repack] May 2026

Here’s an interesting angle on that often surprises people: Why portqry over UDP is tricky Unlike TCP, UDP is connectionless — no handshake, no ACK. So portqry can’t just “connect” to a UDP port to see if it’s listening.

UDP port 33456: FILTERED or NOT LISTENING (no response) Or with a host that sends ICMP unreachable: portqry udp

portqry -n 192.168.1.1 -p udp -e 33456 You might get: Here’s an interesting angle on that often surprises

UDP port 33456: NOT LISTENING (ICMP Port Unreachable) Want to see if something on your own machine is bound to UDP but not responding? UDP is connectionless — no handshake