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Port 663 (purenoise)

IANA assigns port 663 to purenoise: PureNoise.

Well-known (system) port, 0-1023 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
purenoise TCP PureNoise Sam Osa -
purenoise UDP PureNoise Sam Osa -

Check what is listening on port 663

Linux: is anything listening on TCP 663?
sudo ss -tlnp 'sport = :663'
Linux: UDP 663
sudo ss -ulnp 'sport = :663'
Linux / macOS: which process owns the port
sudo lsof -nP -i :663
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':663 '
Windows (Command Prompt)
netstat -ano | findstr :663
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 663 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 663
From Windows
Test-NetConnection HOST -Port 663
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 663

Block port 663 in the firewall

ufw
sudo ufw deny 663/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 663 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 663 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 663' -Direction Inbound -Protocol TCP -LocalPort 663 -Action Block
ufw
sudo ufw deny 663/udp
iptables
sudo iptables -A INPUT -p udp --dport 663 -j DROP
nftables
sudo nft add rule inet filter input udp dport 663 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 663' -Direction Inbound -Protocol UDP -LocalPort 663 -Action Block

Related ports

661hap662pftp664oob-ws-https, asf-secure-rmcp665sun-dr

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