Port 8891Desktop Data UDP 3 (NESS application)

An obscure UDP assignment for Desktop Data UDP 3, described by IANA as a NESS application.

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

also known as ddi-udp-4, NESS application

1 other service is registered on port 8891. compare all 2 →

Technical Details

what runs on :8891

Desktop Data UDP 3 (NESS application) is registered on port :8891 over udp to Fred Yao. 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 :8891

this machine

# linux
sudo ss -ulpn 'sport = :8891'

# macos / bsd
sudo lsof -nP -i :8891

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :8891

another host

sudo nmap -sU -sV -p U:8891 <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 :8891

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

udp

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

security overview

no security notes recorded for :8891 yet

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

Record

iana registry entry

port: :8891
service: Desktop Data UDP 3 (NESS application)
transport: UDP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: uncategorised
usage: IANA describes UDP port 8891 as Desktop Data UDP 3 for a NESS application and lists Fred Yao as the registrant. It has not appeared open in nmap's internet-wide scan data.
lookups: 0rank 993
added: 2026-10-14
updated: 2026-10-14
references: IANA service name registry — port 8891

Something wrong?

This record is maintained by the engineers who use port 8891. 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 2026-10-14.

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 :8891, by lookups.

port	service	proto	category	risk	views
:8888	Sun Answerbook & Alt HTTP	TCP	Web Services	caution	123.9k
:8888	D2GS Admin Console	TCP	Remote Access	caution	83.7k
:8888	NewsEDGE	TCPUDP	Web Services	caution	83.3k
:8888	HTTP Alternative Port	TCP	Web Services	caution	76.5k
:8888	GNUmp3d Streaming HTTP	TCP	Web Services	caution	76.3k
:8888	Earthland Realms 2 Server	TCP	Gaming	caution	73.1k
:8881	Atlasz Secure Server	TCP	Web Services	caution	67.6k
:8882	Atlasz Secure App Server	TCP	Web Services	caution	66.9k

risk mix of the 8 listed

caution100%

0 of 8 encrypted

Port :8891Desktop Data UDP 3 (NESS application)

Technical Details

Security Information

Related Ports

Port 8891Desktop Data UDP 3 (NESS application)