NetDebug Toolkit
Tools Docs Support Terms Privacy
Connectivity

TCP/UDP Connect

Test whether a specific host:port is reachable over TCP or UDP.

🔌

TCP/UDP Connect

portconnect

Input

  • Target: domain or IP address.

Options

  • Protocol:
    • tcp: checks if a TCP handshake can be established.
    • udp: sends a profile-aware UDP probe and evaluates replies.
  • UDP Profile (UDP only): none (default), dns (53), ntp (123), snmp (161), sip (5060), radius (1812), tftp (69), memcached (11211).
  • Port: single port from 1 to 65535. You can always override the suggested profile port.

Output

  • Reachable status (Yes/No/Unknown).
  • Measured latency in milliseconds.
  • Reason line with success context or a concrete failure reason (timeout, refused, unreachable host/network).

Tips

  • Use TCP for clear open/closed behavior on service ports.
  • UDP with none uses an nc-style send check and reports reachable when a datagram is sent successfully.
  • For stricter UDP validation, choose a matching response-based profile (e.g. DNS profile on a DNS server).

Deeplink

netdebug://portconnect?target=8.8.8.8&protocol=udp&udpprofile=dns

Tip: in the app, open the Export menu (the share icon) on this screen and choose Copy Deeplink to copy this link as a Universal Link with your current target and options already filled in.