Port 18243Check Point ClusterXL state backup

TCP port 18243 is assigned to Check Point for router state backup associated with ClusterXL.

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

Technical Details

what runs on :18243

Check Point ClusterXL state backup is registered on port :18243 over tcp to Check Point Software, assigned June 2012. 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 :18243

this machine

# linux
sudo ss -tlpn 'sport = :18243'

# macos / bsd
sudo lsof -nP -i :18243

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :18243

another host

nmap -sV -p T:18243 <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 :18243

risk score

1/ 10safe

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

security averages 2.9 across 438 ports — this one sits 1.9 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

every listening transport is another surface to filter at the edge

security overview

no security notes recorded for :18243 yet

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

Record

iana registry entry

port: :18243
service: Check Point ClusterXL state backup
transport: TCP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: Security Network Services
usage: The IANA assignment identifies this as Check Point router state backup, under the service name clusterxl. I can’t reliably characterize its protocol behavior or typical deployment beyond that assignment.
lookups: 0rank 993
added: 2026-10-18
updated: 2026-10-18
references: IANA service name registry — port 18243

Something wrong?

This record is maintained by the engineers who use port 18243. 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 2026-10-18.

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

all 438 in security →

the 8 most looked-up other ports in security — 438 ports carry that label.

port	service	proto	category	risk	views
:8881	Atlasz Secure Server	TCP	Web Services	caution	67.6k
:443	HTTPS	TCPtls	Web Services	caution	65.9k
:8291	Winbox MikroTik Admin	TCP	Security	caution	62.9k
:3268	Microsoft Global Catalog (GC)	TCPUDP	Security	caution	54.6k
:135	Microsoft EPMAP	TCPUDP	Security	caution	51.9k
:3128	Squid Proxy HTTP	TCP	Web Services	caution	45.8k
:8080	HTTP Alternate	TCP	Web Services	caution	44.9k
:7000	Vuze HTTPS Tracker	TCPtls	Security	caution	28.9k

risk mix of the 8 listed

caution100%

2 of 8 encrypted

Port :18243Check Point ClusterXL state backup

Technical Details

Security Information

Related Ports

Port 18243Check Point ClusterXL state backup