Port 4309Exsequi Appliance Discovery

TCP/UDP 4309 is assigned to Exsequi Appliance Discovery, a service registered by Angelo Masci.

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

also known as dserver

Technical Details

what runs on :4309

Exsequi Appliance Discovery is registered on port :4309 over tcp and udp to Angelo Masci, assigned January 2007. 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 :4309

this machine

# linux
sudo ss -tulpn 'sport = :4309'

# macos / bsd
sudo lsof -nP -i :4309

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :4309

another host

nmap -sV -p T:4309 <host>
sudo nmap -sU -sV -p U:4309 <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 :4309

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 2.6 across 1,515 ports — this one sits 1.6 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 :4309 yet

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

Record

iana registry entry

port: :4309
service: Exsequi Appliance Discovery
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: Network Services
usage: IANA lists this port for Exsequi Appliance Discovery and identifies Angelo Masci as the registrant. No common product or deployment is established for the assignment.
lookups: 0rank 993
added: 2026-10-04
updated: 2026-10-04
references: IANA service name registry — port 4309

Something wrong?

This record is maintained by the engineers who use port 4309. 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 2026-10-04.

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 1,515 in network services →

the 8 most looked-up other ports in network services — 1,515 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 :4309Exsequi Appliance Discovery

Technical Details

Security Information

Related Ports

Port 4309Exsequi Appliance Discovery