Port 4731Remote Capture Protocol

TCP port 4731 is assigned to the Remote Capture Protocol, but no widely encountered implementation is known.

transport
tcp

single transport

in transit
cleartext

payload readable on path

assignment
official

registered with iana

risk
1/10

safe

lookups
0

rank 993 of 5,261 · top 19%

also known as remcap

Technical Details

what runs on :4731

Remote Capture Protocol is registered on port :4731 over tcp to Marc Donner, assigned January 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 :4731

this machine
# linux
sudo ss -tlpn 'sport = :4731'

# macos / bsd
sudo lsof -nP -i :4731

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :4731
another host
nmap -sV -p T:4731 <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 :4731

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 1,568 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 :4731 yet

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

the 8 most looked-up other ports in network services — 1,568 ports carry that label.

risk mix of the 8 listed

  • caution100%

0 of 8 encrypted