Port 283rescap

The IANA-registered rescap service uses TCP and UDP port 283.

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

Technical Details

what runs on :283

rescap is registered on port :283 over tcp and udp to Paul Hoffman. 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 :283

this machine

# linux
sudo ss -tulpn 'sport = :283'

# macos / bsd
sudo lsof -nP -i :283

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :283

another host

nmap -sV -p T:283 <host>
sudo nmap -sU -sV -p U:283 <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 :283

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

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 :283 yet

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

Record

iana registry entry

port: :283
service: rescap
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: uncategorised
usage: Port 283 is assigned by IANA to the rescap service over TCP and UDP. The assignment is registered to Paul Hoffman, but no further deployment or protocol usage is documented here.
lookups: 0rank 993
added: 2026-09-16
updated: 2026-09-16
references: IANA service name registry — port 283

Something wrong?

This record is maintained by the engineers who use port 283. 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 2026-09-16.

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 :283, by lookups.

port	service	proto	category	risk	views
:311	Mac OS X Server Admin	TCP	Web Services	caution	23.7k
:264	Border Gateway Multicast Protocol	TCPUDP	Network Services	caution	12.2k
:323	Internet Message Mapping Protocol (IMMP)	TCPUDP	Email	caution	9.0k
:220	IMAP v3	TCPUDP	Email	caution	8.6k
:256	2DEV 2SP	TCPUDP	Network Services	caution	7.0k
:308	Novastor Backup	TCP	File Transfer	caution	6.4k
:259	Efficient Short Remote Operations (ESRO)	TCPUDP	Network Services	caution	5.8k
:318	PKIX Time Stamp Protocol	TCPUDP	Security	safe	5.7k

risk mix of the 8 listed

safe13%
caution88%

0 of 8 encrypted

Port :283rescap

Technical Details

Security Information

Related Ports

Port 283rescap