Port 2738NDL TCP-OSI Gateway

Port 2738 is assigned to the NDL TCP-OSI Gateway, registered to Martin Norman.

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

also known as ndl-tcp-ois-gw

Technical Details

what runs on :2738

NDL TCP-OSI Gateway is registered on port :2738 over tcp and udp to Martin Norman. 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 :2738

this machine

# linux
sudo ss -tulpn 'sport = :2738'

# macos / bsd
sudo lsof -nP -i :2738

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :2738

another host

nmap -sV -p T:2738 <host>
sudo nmap -sU -sV -p U:2738 <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 :2738

risk score

1/ 10safe

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

network services averages 2.7 across 1,327 ports — this one sits 1.7 below.

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 :2738 yet

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

Record

iana registry entry

port: :2738
service: NDL TCP-OSI Gateway
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: Network Services
usage: IANA assigns TCP and UDP port 2738 to the NDL TCP-OSI Gateway and lists Martin Norman as the registrant. No broader deployment or commonly encountered implementation is established here.
lookups: 0rank 993
added: 2026-09-24
updated: 2026-09-24
references: IANA service name registry — port 2738

Something wrong?

This record is maintained by the engineers who use port 2738. 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 2026-09-24.

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

all 1,327 in network services →

the 8 most looked-up other ports in network services — 1,327 ports carry that label.

port	service	proto	category	risk	views
:9080	Groove RPC	TCPUDP	Web Services	caution	70.8k
:6543	Jetnet	UDP	Network Services	caution	65.3k
:5938	TeamViewer	TCPUDP	Remote Access	caution	65.0k
:8291	Winbox MikroTik Admin	TCP	Security	caution	62.9k
:3233	WhiskerControl Protocol	TCPUDP	Network Services	caution	61.9k
:3268	Microsoft Global Catalog (GC)	TCPUDP	Security	caution	54.6k
:135	Microsoft EPMAP	TCPUDP	Security	caution	51.9k
:3128	Tatsoft Default HTTP Proxy	TCP	Web Services	caution	46.8k

risk mix of the 8 listed

caution100%

0 of 8 encrypted

Port :2738NDL TCP-OSI Gateway

Technical Details

Security Information

Related Ports

Port 2738NDL TCP-OSI Gateway