- Serve it over HTTPS only and check the HTTP security headers.
- Keep admin consoles and development servers off the Internet.
- Patch the application server and remove default credentials and sample apps.
Port 16021: Filemaker Java Web Publishing Core Binary
Port 16021 is assigned by IANA to jwpc-bin (Filemaker Java Web Publishing Core Binary).
16021
How jwpc-bin works
WebA browser sends an HTTP request to port 16021 and the jwpc-bin server sends the page back.
- 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
- Web
Is port 16021 dangerous?
We have no specific security note for port 16021. Its risk depends on the program actually listening on it. General advice for web services:
IANA registry entries for port 16021
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| jwpc-bin | 16021 | TCP | Filemaker Java Web Publishing Core Binary | - | 2010-05-12 |
| - | 16021 | - | Reserved | - | - |
// source: IANA service name and port number registry
Which program uses port 16021, and is it reachable?
Linux
sudo ss -ltnup 'sport = :16021' # process listening on 16021
sudo lsof -nP -i :16021macOS
sudo lsof -nP -i :16021
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 16021 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 16021 netstat -ano | findstr :16021
From another machine
nmap -p 16021 -sV <host> nc -zv <host> 16021
Block it in the firewall
sudo ufw deny 16021/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 16021" -Direction Inbound -LocalPort 16021 -Protocol TCP -Action Block # Windows
What is port 16021 used for?
Port 16021 is assigned by IANA to jwpc-bin (Filemaker Java Web Publishing Core Binary).
Is port 16021 TCP or UDP?
Port 16021 is registered for TCP.
Is it safe to open port 16021?
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. Serve it over HTTPS only and check the HTTP security headers.
How do I check if port 16021 is open?
On Linux run "ss -ltnup 'sport = :16021'", on macOS "lsof -nP -i :16021", and on Windows "netstat -ano | findstr :16021" to see the local process. From another machine, "nmap -p 16021 <host>" shows whether it is reachable.
Other web ports
:443 HTTPS tcp · udp · sctp · low risk :80 HTTP tcp · udp · sctp · moderate risk :8080 HTTP alternate tcp · udp · high risk :8443 HTTPS alternate tcp · udp · moderate risk :3000 Dev servers / Grafana tcp · udp · moderate risk :5000 Flask / Docker registry / UPnP tcp · udp · moderate risk :8000 HTTP alternate (dev) tcp · udp · moderate risk :8888 Jupyter / HTTP alternate tcp · udp · high risk