Port 11321Arena Server

An obscure Arena Server listener assigned on TCP and UDP; no common deployment or public-facing protocol is known.

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

Technical Details

what runs on :11321

Arena Server is registered on port :11321 over tcp and udp to Earl Brannigan. 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 :11321

this machine

# linux
sudo ss -tulpn 'sport = :11321'

# macos / bsd
sudo lsof -nP -i :11321

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :11321

another host

nmap -sV -p T:11321 <host>
sudo nmap -sU -sV -p U:11321 <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 :11321

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 :11321 yet

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

Record

iana registry entry

port: :11321
service: Arena Server
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: uncategorised
usage: IANA assigns this port for “Arena Server Listen” and lists Earl Brannigan as the registrant. No widely recognized product or deployment associated with the assignment is known.
lookups: 0rank 993
added: 2026-10-17
updated: 2026-10-17
references: IANA service name registry — port 11321

Something wrong?

This record is maintained by the engineers who use port 11321. 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 2026-10-17.

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 :11321, by lookups.

port	service	proto	category	risk	views
:11371	OpenPGP Keyserver		Security	caution	22.5k
:11294	Blood Quest Online		Gaming	caution	6.7k
:11319	IMIP	TCPUDP	—	safe	0
:11320	IMIP Channels	TCPUDP	—	safe	0
:11367	ATM UHAS	TCPUDP	—	safe	0

risk mix of the 5 listed

safe60%
caution40%

0 of 5 encrypted

Port :11321Arena Server

Technical Details

Security Information

Related Ports

Port 11321Arena Server