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Port 3337 (directv-catlg)

IANA assigns port 3337 to directv-catlg: Direct TV Data Catalog.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
directv-catlg TCP Direct TV Data Catalog Michael Friedman -
directv-catlg UDP Direct TV Data Catalog Michael Friedman -

Check what is listening on port 3337

Linux: is anything listening on TCP 3337?
sudo ss -tlnp 'sport = :3337'
Linux: UDP 3337
sudo ss -ulnp 'sport = :3337'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3337
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3337 '
Windows (Command Prompt)
netstat -ano | findstr :3337
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3337 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3337
From Windows
Test-NetConnection HOST -Port 3337
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3337

Block port 3337 in the firewall

ufw
sudo ufw deny 3337/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3337 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3337 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3337' -Direction Inbound -Protocol TCP -LocalPort 3337 -Action Block
ufw
sudo ufw deny 3337/udp
iptables
sudo iptables -A INPUT -p udp --dport 3337 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3337 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3337' -Direction Inbound -Protocol UDP -LocalPort 3337 -Action Block

Related ports

3335directv-soft3336directv-tick3338anet-b3339anet-l

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