Port 43191Reconnoiter Agent Data Transport

TCP port assigned to Reconnoiter's agent data transport.

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

also known as noit-transport

Technical Details

what runs on :43191

Reconnoiter Agent Data Transport is registered on port :43191 over tcp to Theo Schlossnagle, assigned May 2009. 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 :43191

this machine

# linux
sudo ss -tlpn 'sport = :43191'

# macos / bsd
sudo lsof -nP -i :43191

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :43191

another host

nmap -sV -p T:43191 <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 :43191

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 2,008 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

every listening transport is another surface to filter at the edge

security overview

no security notes recorded for :43191 yet

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

Record

iana registry entry

port: :43191
service: Reconnoiter Agent Data Transport
transport: TCP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: Network Services
usage: The IANA assignment identifies this as Reconnoiter Agent Data Transport. The assignment is registered to Theo Schlossnagle; the port has not appeared open in the cited nmap scan data.
lookups: 0rank 993
added: 2026-10-20
updated: 2026-10-20
references: IANA service name registry — port 43191

Something wrong?

This record is maintained by the engineers who use port 43191. 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 2026-10-20.

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 2,008 in network services →

the 8 most looked-up other ports in network services — 2,008 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 :43191Reconnoiter Agent Data Transport

Technical Details

Security Information

Related Ports

Port 43191Reconnoiter Agent Data Transport