HTTPfy

Port 3840 (flirtmitmir)

IANA assigns port 3840 to flirtmitmir: www.FlirtMitMir.de.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
flirtmitmir TCP www.FlirtMitMir.de Carsten Falticska -
flirtmitmir UDP www.FlirtMitMir.de Carsten Falticska -

Registry dates for this port: registered 2003-11.

Check what is listening on port 3840

Linux: is anything listening on TCP 3840?
sudo ss -tlnp 'sport = :3840'
Linux: UDP 3840
sudo ss -ulnp 'sport = :3840'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3840
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3840 '
Windows (Command Prompt)
netstat -ano | findstr :3840
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3840 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3840
From Windows
Test-NetConnection HOST -Port 3840
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3840

Block port 3840 in the firewall

ufw
sudo ufw deny 3840/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3840 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3840 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3840' -Direction Inbound -Protocol TCP -LocalPort 3840 -Action Block
ufw
sudo ufw deny 3840/udp
iptables
sudo iptables -A INPUT -p udp --dport 3840 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3840 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3840' -Direction Inbound -Protocol UDP -LocalPort 3840 -Action Block

Related ports

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