Port 516Videotex

Legacy videotex traffic is assigned to TCP and UDP port 516.

transport: tcp · udp
in transit: cleartext
assignment: official
risk: 1/10
lookups: 0

Technical Details

what runs on :516

no technical write-up for :516 yet

the handshake, the implementations you meet in the wild, the flags that matter. we have the registry entry — the detail comes from the engineers who run it.

add technical details

Security Information

exposure of :516

risk score

1/ 10safe

routine exposure. this port is rarely the way in on its own — keep it patched and logged and move on.

in transit

cleartext

credentials and payloads are readable by anyone on path

assignment

official

registered with iana for this service — scanners fingerprint it by number

reachable over

tcp · udp

udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite

security overview

no security notes recorded for :516 yet

known exploits, hardening advice, what a compromise looks like — suggest an edit if you know its exposure.

Record

iana registry entry

port: :516
service: Videotex
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: uncategorised
usage: IANA assigns TCP and UDP port 516 to the videotex service name. The assignment is registered to Daniel Mavrakis, but there is no established modern deployment or product context documented here.
lookups: 0rank 994
added: 2026-08-23
updated: 2026-08-23
references: IANA service name registry — port 516

Something wrong?

This record is maintained by the engineers who use port 516. Every field on it is editable — change what's wrong, say how you know, and a reviewer publishes it, usually within a minute. Last touched 2026-08-23.

01edit any field on a page of its own
02a model checks it for accuracy and spam
03clean and confident goes live immediately

edit this record →back to the registry

Related Ports

browse categories →

ports registered around :516, by lookups.

port	service	proto	category	risk	views
:548	Apple Filing Protocol	TCP	File Transfer	caution	36.8k
:475	tcpnethaspsrv	TCP	Security	caution	20.7k
:502	Modbus Protocol	TCPUDP	Network Services	caution	19.2k
:563	NNTPS	TCPUDPtls	Web Services	safe	18.1k
:546	DHCPv6 Client	TCPUDP	Network Services	caution	16.6k
:547	DHCPv6 Server	TCPUDP	Network Services	caution	14.5k
:533	Netwall Emergency Broadcasts	UDP	Security	caution	14.3k
:502	Modbus	TCPUDP	Network Services	caution	13.7k

risk mix of the 8 listed

safe13%
caution88%

1 of 8 encrypted

Port :516Videotex

Technical Details

Security Information

Related Ports

Port 516Videotex