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Port 1800 (ansys-lm)

IANA assigns port 1800 to ansys-lm: ANSYS-License manager.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
ansys-lm TCP ANSYS-License manager Suzanne Lorrin 2 -
ansys-lm UDP ANSYS-License manager Suzanne Lorrin 2 -

Check what is listening on port 1800

Linux: is anything listening on TCP 1800?
sudo ss -tlnp 'sport = :1800'
Linux: UDP 1800
sudo ss -ulnp 'sport = :1800'
Linux / macOS: which process owns the port
sudo lsof -nP -i :1800
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':1800 '
Windows (Command Prompt)
netstat -ano | findstr :1800
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 1800 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 1800
From Windows
Test-NetConnection HOST -Port 1800
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 1800

Block port 1800 in the firewall

ufw
sudo ufw deny 1800/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 1800 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 1800 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 1800' -Direction Inbound -Protocol TCP -LocalPort 1800 -Action Block
ufw
sudo ufw deny 1800/udp
iptables
sudo iptables -A INPUT -p udp --dport 1800 -j DROP
nftables
sudo nft add rule inet filter input udp dport 1800 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 1800' -Direction Inbound -Protocol UDP -LocalPort 1800 -Action Block

Related ports

1798etp1799netrisk1801msmq1802concomp1

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