Port 1690ng-umds

ng-umds is an IANA-registered TCP/UDP service on port 1690 with no documented public deployment.

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

Technical Details

what runs on :1690

ng-umds is registered on port :1690 over tcp and udp to Louis E Simard. 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 :1690

this machine

# linux
sudo ss -tulpn 'sport = :1690'

# macos / bsd
sudo lsof -nP -i :1690

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :1690

another host

nmap -sV -p T:1690 <host>
sudo nmap -sU -sV -p U:1690 <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 :1690

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 :1690 yet

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

Record

iana registry entry

port: :1690
service: ng-umds
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: uncategorised
usage: Port 1690 is assigned to the ng-umds service over TCP and UDP. The assignment is registered to Louis E Simard, but there is no additional registry information or observed internet-wide deployment.
lookups: 0rank 993
added: 2026-09-18
updated: 2026-09-18
references: IANA service name registry — port 1690

Something wrong?

This record is maintained by the engineers who use port 1690. 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 2026-09-18.

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 :1690, by lookups.

port	service	proto	category	risk	views
:1720	H.323 Signaling	TCP	Network Services	caution	26.5k
:1701	L2TP & L2F	UDP	Security	caution	15.1k
:1645	RADIUS Authentication (Cisco/Juniper)	TCPUDP	Security	caution	15.1k
:1646	RADIUS Accounting	TCPUDP	Security	caution	13.1k
:1716	America's Army MMO	TCP	Network Services	caution	12.6k
:1723	PPTP	TCPUDP	Security	caution	11.3k
:1719	H.323 RAS	UDP	Network Services	caution	9.2k
:1677	Novell GroupWise	TCPUDP	Email	caution	7.5k

risk mix of the 8 listed

caution100%

0 of 8 encrypted

Port :1690ng-umds

Technical Details

Security Information

Related Ports

Port 1690ng-umds