Port 51413 (Transmission BitTorrent)

Default peer port of the Transmission BitTorrent client.

Dynamic / private (ephemeral) port, 49152-65535 TCPUDP Peer-to-peer Meant to face the internet

What port 51413 is used for

Default peer port of the Transmission BitTorrent client.

Meant to face the internet. Exposes your IP to peers; keep the web UI (9091) separate and password-protected.

Port 51413 is in the dynamic range, which IANA never assigns. The usage above is unofficial but widespread.

Linux: is anything listening on TCP 51413?

sudo ss -tlnp 'sport = :51413'

Linux: UDP 51413

sudo ss -ulnp 'sport = :51413'

Linux / macOS: which process owns the port

sudo lsof -nP -i :51413

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':51413 '

Windows (Command Prompt)

netstat -ano | findstr :51413

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 51413 -State Listen | Select LocalAddress,OwningProcess

From another machine

nc -vz -w 5 HOST 51413

From Windows

Test-NetConnection HOST -Port 51413

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

nc -vzu -w 5 HOST 51413

ufw

sudo ufw allow 51413/tcp

iptables

sudo iptables -A INPUT -p tcp --dport 51413 -j ACCEPT

nftables

sudo nft add rule inet filter input tcp dport 51413 accept

Windows Firewall

New-NetFirewallRule -DisplayName 'Allow TCP 51413' -Direction Inbound -Protocol TCP -LocalPort 51413 -Action Allow

ufw

sudo ufw allow 51413/udp

iptables

sudo iptables -A INPUT -p udp --dport 51413 -j ACCEPT

nftables

sudo nft add rule inet filter input udp dport 51413 accept

Windows Firewall

New-NetFirewallRule -DisplayName 'Allow UDP 51413' -Direction Inbound -Protocol UDP -LocalPort 51413 -Action Allow

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