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Port 2237 (optech-port1-lm)

IANA assigns port 2237 to optech-port1-lm: Optech Port1 License Manager.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
optech-port1-lm TCP Optech Port1 License Manager Gerard Cannie -
optech-port1-lm UDP Optech Port1 License Manager Gerard Cannie -

Check what is listening on port 2237

Linux: is anything listening on TCP 2237?
sudo ss -tlnp 'sport = :2237'
Linux: UDP 2237
sudo ss -ulnp 'sport = :2237'
Linux / macOS: which process owns the port
sudo lsof -nP -i :2237
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':2237 '
Windows (Command Prompt)
netstat -ano | findstr :2237
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 2237 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 2237
From Windows
Test-NetConnection HOST -Port 2237
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 2237

Block port 2237 in the firewall

ufw
sudo ufw deny 2237/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 2237 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 2237 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 2237' -Direction Inbound -Protocol TCP -LocalPort 2237 -Action Block
ufw
sudo ufw deny 2237/udp
iptables
sudo iptables -A INPUT -p udp --dport 2237 -j DROP
nftables
sudo nft add rule inet filter input udp dport 2237 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 2237' -Direction Inbound -Protocol UDP -LocalPort 2237 -Action Block

Related ports

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