HTTPfy

Port 3120 (d2000webserver)

IANA assigns port 3120 to d2000webserver: D2000 Webserver Port.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
d2000webserver TCP D2000 Webserver Port Tomas Rajcan -
d2000webserver UDP D2000 Webserver Port Tomas Rajcan -

Check what is listening on port 3120

Linux: is anything listening on TCP 3120?
sudo ss -tlnp 'sport = :3120'
Linux: UDP 3120
sudo ss -ulnp 'sport = :3120'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3120
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3120 '
Windows (Command Prompt)
netstat -ano | findstr :3120
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3120 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3120
From Windows
Test-NetConnection HOST -Port 3120
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3120

Block port 3120 in the firewall

ufw
sudo ufw deny 3120/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3120 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3120 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3120' -Direction Inbound -Protocol TCP -LocalPort 3120 -Action Block
ufw
sudo ufw deny 3120/udp
iptables
sudo iptables -A INPUT -p udp --dport 3120 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3120 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3120' -Direction Inbound -Protocol UDP -LocalPort 3120 -Action Block

Related ports

3118pkagent3119d2000kernel3121pcmk-remote3122vtr-emulator

All port numbers · Open port checker
Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.