Port 3859 (nav-port)

IANA assigns port 3859 to nav-port: Navini Port.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference

nav-port TCP Navini Port Chris Sanders -

nav-port UDP Navini Port Chris Sanders -

Registry dates for this port: registered 2003-08.

Linux: is anything listening on TCP 3859?

sudo ss -tlnp 'sport = :3859'

Linux: UDP 3859

sudo ss -ulnp 'sport = :3859'

Linux / macOS: which process owns the port

sudo lsof -nP -i :3859

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':3859 '

Windows (Command Prompt)

netstat -ano | findstr :3859

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 3859 -State Listen | Select LocalAddress,OwningProcess

From another machine

nc -vz -w 5 HOST 3859

From Windows

Test-NetConnection HOST -Port 3859

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

nc -vzu -w 5 HOST 3859

ufw

sudo ufw deny 3859/tcp

iptables

sudo iptables -A INPUT -p tcp --dport 3859 -j DROP

nftables

sudo nft add rule inet filter input tcp dport 3859 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block TCP 3859' -Direction Inbound -Protocol TCP -LocalPort 3859 -Action Block

ufw

sudo ufw deny 3859/udp

iptables

sudo iptables -A INPUT -p udp --dport 3859 -j DROP

nftables

sudo nft add rule inet filter input udp dport 3859 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block UDP 3859' -Direction Inbound -Protocol UDP -LocalPort 3859 -Action Block

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Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.