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Port 3377 (cogsys-lm)

IANA assigns port 3377 to cogsys-lm: Cogsys Network License Manager.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
cogsys-lm TCP Cogsys Network License Manager Simon Chinnick -
cogsys-lm UDP Cogsys Network License Manager Simon Chinnick -

Check what is listening on port 3377

Linux: is anything listening on TCP 3377?
sudo ss -tlnp 'sport = :3377'
Linux: UDP 3377
sudo ss -ulnp 'sport = :3377'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3377
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3377 '
Windows (Command Prompt)
netstat -ano | findstr :3377
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3377 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3377
From Windows
Test-NetConnection HOST -Port 3377
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3377

Block port 3377 in the firewall

ufw
sudo ufw deny 3377/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3377 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3377 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3377' -Direction Inbound -Protocol TCP -LocalPort 3377 -Action Block
ufw
sudo ufw deny 3377/udp
iptables
sudo iptables -A INPUT -p udp --dport 3377 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3377 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3377' -Direction Inbound -Protocol UDP -LocalPort 3377 -Action Block

Related ports

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