Port 4445 (upnotifyp)

IANA assigns port 4445 to upnotifyp: UPNOTIFYP.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference

upnotifyp TCP UPNOTIFYP Mark Fox -

upnotifyp UDP UPNOTIFYP Mark Fox -

Linux: is anything listening on TCP 4445?

sudo ss -tlnp 'sport = :4445'

Linux: UDP 4445

sudo ss -ulnp 'sport = :4445'

Linux / macOS: which process owns the port

sudo lsof -nP -i :4445

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':4445 '

Windows (Command Prompt)

netstat -ano | findstr :4445

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 4445 -State Listen | Select LocalAddress,OwningProcess

From another machine

nc -vz -w 5 HOST 4445

From Windows

Test-NetConnection HOST -Port 4445

UDP probe (no reply does not prove it is closed)

nc -vzu -w 5 HOST 4445

ufw

sudo ufw deny 4445/tcp

iptables

sudo iptables -A INPUT -p tcp --dport 4445 -j DROP

nftables

sudo nft add rule inet filter input tcp dport 4445 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block TCP 4445' -Direction Inbound -Protocol TCP -LocalPort 4445 -Action Block

ufw

sudo ufw deny 4445/udp

iptables

sudo iptables -A INPUT -p udp --dport 4445 -j DROP

nftables

sudo nft add rule inet filter input udp dport 4445 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block UDP 4445' -Direction Inbound -Protocol UDP -LocalPort 4445 -Action Block

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