Listen on TCP/443 with netcat

Wed, 04 Nov 2026 13:00:00 +0100

During ZTNA testing, I used a temporary netcat listener on a Linux test host to check whether a remote connection could reach TCP/443.

nc -lvnp 443

When the connection appeared in the listener, I knew the TCP session had reached the test port. I then checked the ZTNA policy logs to confirm which access rule matched. Netcat alone cannot identify the policy that allowed the traffic.

This was a TCP connectivity check, not an HTTPS/TLS test. Binding to port 443 may require elevated permissions on Linux, and netcat syntax can vary by implementation.

Policy Validation on Ivan Versluis — Networknet

Listen on TCP/443 with netcat