Port 3718OPUS Server Port

Port 3718 is assigned to the OPUS Server service, but its protocol and common deployments are not publicly established.

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

also known as opus-services

Technical Details

what runs on :3718

OPUS Server Port is registered on port :3718 over tcp and udp to Detlef Stoever, assigned March 2003. We don't have a technical write-up for it beyond the IANA registry entry.

In nmap's internet-wide scan data this port is never observed open, so if it's open on your network it's more likely a custom or misconfigured service than the registered one.

find what's listening on :3718

this machine

# linux
sudo ss -tulpn 'sport = :3718'

# macos / bsd
sudo lsof -nP -i :3718

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :3718

another host

nmap -sV -p T:3718 <host>
sudo nmap -sU -sV -p U:3718 <host>

run it? the handshake, the implementations you meet in the wild and the flags that matter come from the engineers who do.

add technical details

Security Information

exposure of :3718

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 :3718 yet

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

Record

iana registry entry

port: :3718
service: OPUS Server Port
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: uncategorised
usage: IANA assigns TCP and UDP port 3718 to OPUS Server and lists Detlef Stoever as the registrant. No widely encountered deployment or additional established use is known.
lookups: 0rank 993
added: 2026-10-01
updated: 2026-10-01
references: IANA service name registry — port 3718

Something wrong?

This record is maintained by the engineers who use port 3718. 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 2026-10-01.

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 :3718, by lookups.

port	service	proto	category	risk	views
:3702	WS-Discovery	TCPUDP	Network Services	caution	16.5k
:3724	Club Penguin	TCP	Gaming	caution	10.4k
:3724	World of Warcraft	TCPUDP	Network Services	caution	10.2k
:3723	Battle.net Gaming	TCPUDP	Network Services	caution	9.2k
:3689	DAAP (iTunes Music Sharing)	TCP	Streaming	caution	9.2k
:3690	Subversion (SVN)	TCPUDP	File Transfer	caution	5.4k
:3721	Xsync	TCPUDP	—	safe	0
:3664	UPS Engine	TCPUDP	System	safe	0

risk mix of the 8 listed

safe25%
caution75%

0 of 8 encrypted

Port :3718OPUS Server Port

Technical Details

Security Information

Related Ports

Port 3718OPUS Server Port