- 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 21337: Xahau P2P network protocol
Port 21337 is assigned by IANA to xahaud (Xahau P2P network protocol).
21337
How xahaud works
Other servicesThe client sends a request to port 21337 and the xahaud service answers.
- Transport
- TCP
- Exposure risk
- not rated depends on the program listening
- Encryption
- Unknownnot stated by the registry
- IANA status
- Assigned1 registered service
- Range
- Registered (1024-49151)
- Category
- Other services
Is port 21337 dangerous?
We have no specific security note for port 21337. Its risk depends on the program actually listening on it. General advice for other services services:
IANA registry entries for port 21337
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| xahaud | 21337 | TCP | Xahau P2P network protocol | https://xahau.network | 2025-10-16 |
| - | 21337 | - | Reserved | - | - |
// source: IANA service name and port number registry
Which program uses port 21337, and is it reachable?
Linux
sudo ss -ltnup 'sport = :21337' # process listening on 21337
sudo lsof -nP -i :21337macOS
sudo lsof -nP -i :21337
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 21337 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 21337 netstat -ano | findstr :21337
From another machine
nmap -p 21337 -sV <host> nc -zv <host> 21337
Block it in the firewall
sudo ufw deny 21337/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 21337" -Direction Inbound -LocalPort 21337 -Protocol TCP -Action Block # Windows
What is port 21337 used for?
Port 21337 is assigned by IANA to xahaud (Xahau P2P network protocol).
Is port 21337 TCP or UDP?
Port 21337 is registered for TCP.
Is it safe to open port 21337?
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 21337 is open?
On Linux run "ss -ltnup 'sport = :21337'", on macOS "lsof -nP -i :21337", and on Windows "netstat -ano | findstr :21337" to see the local process. From another machine, "nmap -p 21337 <host>" shows whether it is reachable.
Other other services ports
:4444 Metasploit default / krb524 tcp · udp · high risk :31337 Back Orifice / elite tcp · udp · high risk :1 TCP Port Service Multiplexer tcp · udp :5 Remote Job Entry tcp · udp :9 Discard tcp · udp · sctp · dccp :11 Active Users tcp · udp :17 Quote of the Day tcp · udp :18 Message Send Protocol (historic) tcp · udp