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Port 13820 (dsmcc-passthru)

IANA assigns port 13820 to dsmcc-passthru: DSMCC Pass-Thru Messages.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
dsmcc-passthru TCP DSMCC Pass-Thru Messages Tim Addington ISO/IEC 13818-6 MPEG-2 DSM-CC
dsmcc-passthru UDP DSMCC Pass-Thru Messages Tim Addington ISO/IEC 13818-6 MPEG-2 DSM-CC

Check what is listening on port 13820

Linux: is anything listening on TCP 13820?
sudo ss -tlnp 'sport = :13820'
Linux: UDP 13820
sudo ss -ulnp 'sport = :13820'
Linux / macOS: which process owns the port
sudo lsof -nP -i :13820
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':13820 '
Windows (Command Prompt)
netstat -ano | findstr :13820
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 13820 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 13820
From Windows
Test-NetConnection HOST -Port 13820
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 13820

Block port 13820 in the firewall

ufw
sudo ufw deny 13820/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 13820 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 13820 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 13820' -Direction Inbound -Protocol TCP -LocalPort 13820 -Action Block
ufw
sudo ufw deny 13820/udp
iptables
sudo iptables -A INPUT -p udp --dport 13820 -j DROP
nftables
sudo nft add rule inet filter input udp dport 13820 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 13820' -Direction Inbound -Protocol UDP -LocalPort 13820 -Action Block

Related ports

13818dsmcc-config13819dsmcc-session13821dsmcc-download13822dsmcc-ccp

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