Port 3251Sys Scanner

An obscure service assignment named Sys Scanner, with no widely established public protocol or common deployment.

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

Technical Details

what runs on :3251

Sys Scanner is registered on port :3251 over tcp and udp to Dick Georges, assigned February 2002. 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 :3251

this machine

# linux
sudo ss -tulpn 'sport = :3251'

# macos / bsd
sudo lsof -nP -i :3251

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :3251

another host

nmap -sV -p T:3251 <host>
sudo nmap -sU -sV -p U:3251 <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 :3251

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 :3251 yet

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

Record

iana registry entry

port: :3251
service: Sys Scanner
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: uncategorised
usage: IANA assigns TCP and UDP port 3251 to “Sys Scanner,” registered to Dick Georges on 2002-02-01. No broadly documented implementation or routine internet-facing use is established.
lookups: 0rank 993
added: 2026-09-28
updated: 2026-09-28
references: IANA service name registry — port 3251

Something wrong?

This record is maintained by the engineers who use port 3251. 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 2026-09-28.

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 :3251, by lookups.

port	service	proto	category	risk	views
:3233	WhiskerControl Protocol	TCPUDP	Network Services	caution	61.9k
:3268	Microsoft Global Catalog (GC)	TCPUDP	Security	caution	54.6k
:3269	Microsoft Global Catalog SSL	TCPUDPtls	Security	caution	26.4k
:3283	Apple Remote Desktop Reporting	TCP	Remote Access	caution	26.0k
:3299	SAP Router	TCPtls	Network Services	caution	13.8k
:3306	MySQL	TCPUDP	Databases	caution	13.6k
:3260	iSCSI Target Service	TCP	Databases	caution	11.1k
:3235	Galaxy Network Service	TCPUDP	Web Services	caution	9.5k

risk mix of the 8 listed

caution100%

2 of 8 encrypted

Port :3251Sys Scanner

Technical Details

Security Information

Related Ports

Port 3251Sys Scanner