- Close the port if nothing on the host needs it.
- Identify the process that listens on it (commands below) before opening it in a firewall.
- Expose a service only to the networks that use it.
Port 283: rescap
Port 283 is assigned by IANA to rescap (rescap).
How rescap works
Other servicesThe client sends a request to port 283 and the rescap service answers.
- Transport
- TCP · UDP
- Exposure risk
- not rated depends on the program listening
- Encryption
- Unknownnot stated by the registry
- IANA status
- Assigned1 registered service
- Range
- Well-known (0-1023)
- Category
- Other services
Is port 283 dangerous?
We have no specific security note for port 283. Its risk depends on the program actually listening on it. General advice for other services services:
IANA registry entries for port 283
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| rescap | 283 | TCP, UDP | rescap | - | - |
// source: IANA service name and port number registry
Which program uses port 283, and is it reachable?
Linux
sudo ss -ltnup 'sport = :283' # process listening on 283
sudo lsof -nP -i :283macOS
sudo lsof -nP -i :283
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 283 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 283 netstat -ano | findstr :283
From another machine
nmap -p 283 -sV <host> sudo nmap -sU -p 283 <host> nc -zv <host> 283
Block it in the firewall
sudo ufw deny 283/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 283" -Direction Inbound -LocalPort 283 -Protocol TCP -Action Block # Windows
What is port 283 used for?
Port 283 is assigned by IANA to rescap (rescap).
Is port 283 TCP or UDP?
Port 283 is registered for TCP and UDP.
Is it safe to open port 283?
It depends on the program that listens on it. Open it only for a service you know and only to the networks that need it. Close the port if nothing on the host needs it.
How do I check if port 283 is open?
On Linux run "ss -ltnup 'sport = :283'", on macOS "lsof -nP -i :283", and on Windows "netstat -ano | findstr :283" to see the local process. From another machine, "nmap -p 283 <host>" shows whether it is reachable.