HTTPfy

Port 3664 (ups-engine)

IANA assigns port 3664 to ups-engine: UPS Engine Port.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
ups-engine TCP UPS Engine Port - -
ups-engine UDP UPS Engine Port - -

Check what is listening on port 3664

Linux: is anything listening on TCP 3664?
sudo ss -tlnp 'sport = :3664'
Linux: UDP 3664
sudo ss -ulnp 'sport = :3664'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3664
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3664 '
Windows (Command Prompt)
netstat -ano | findstr :3664
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3664 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3664
From Windows
Test-NetConnection HOST -Port 3664
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3664

Block port 3664 in the firewall

ufw
sudo ufw deny 3664/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3664 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3664 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3664' -Direction Inbound -Protocol TCP -LocalPort 3664 -Action Block
ufw
sudo ufw deny 3664/udp
iptables
sudo iptables -A INPUT -p udp --dport 3664 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3664 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3664' -Direction Inbound -Protocol UDP -LocalPort 3664 -Action Block

Related ports

3662pserver3663dtp3665ent-engine3666eserver-pap

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