Port 11751Intrepid SSL

TCP and UDP port 11751 is assigned to Intrepid SSL, a service registered to Robert Eden with no established common deployment.

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

Technical Details

what runs on :11751

Intrepid SSL is registered on port :11751 over tcp and udp to Robert Eden, assigned March 2003. 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 :11751

this machine

# linux
sudo ss -tulpn 'sport = :11751'

# macos / bsd
sudo lsof -nP -i :11751

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :11751

another host

nmap -sV -p T:11751 <host>
sudo nmap -sU -sV -p U:11751 <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 :11751

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

encrypted

payloads are protected on the wire

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 :11751 yet

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

Record

iana registry entry

port: :11751
service: Intrepid SSL
transport: TCPUDP
encryption: tls / encrypted
assignment: iana registered
risk: 1/10safe
category: uncategorised
usage: IANA assigns this port to Intrepid SSL, registered to Robert Eden in 2003. No common deployment is established, and it has not appeared open in the cited internet-wide scan data.
lookups: 0rank 993
added: 2026-10-17
updated: 2026-10-17
references: IANA service name registry — port 11751

Something wrong?

This record is maintained by the engineers who use port 11751. 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 :11751, by lookups.

port	service	proto	category	risk
:11720	H.323 Call Control Signalling Alternate	TCPUDP	Voice and Chat	caution
:11723	EMC XtremSW Distributed Cache	TCPUDP	—	safe
:11796	LanSchool Multipoint	UDP	Network Services	safe

risk mix of the 3 listed

safe67%
caution33%

0 of 3 encrypted

Port :11751Intrepid SSL

Technical Details

Security Information

Related Ports

Port 11751Intrepid SSL