WHATPORT(444) whatport.net WHATPORT(444)
444

SNPP (Simple Network Paging Protocol)

The registered home of pager messaging — but in practice usually an alternate HTTPS or admin port.

TCP IANA: snpp

Description

SNPP (RFC 1861) is a plain-text, SMTP-shaped protocol for delivering messages to pagers: connect, PAGE the recipient ID, MESS the text, SEND. Paging carriers ran it into the 2000s and a few emergency-notification systems still do. Far more often, though, an open 444 is something else entirely — administrators reach for it as a spare HTTPS or management port because it sits just past 443 and is easy to remember. Check whether it speaks TLS before assuming SNPP.

Exposed to the internet?

Expose with care

SNPP itself is unencrypted and historically accepted messages without authentication; if the listener is really an admin web UI on 444, judge it as you would any exposed management plane.

Check it yourself

$ printf 'QUIT\r\n' | nc -v -w 5 TARGET 444

See also

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