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Port 373 (legent-1)

IANA assigns port 373 to legent-1: Legent Corporation.

Well-known (system) port, 0-1023 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
legent-1 TCP Legent Corporation - -
legent-1 UDP Legent Corporation - -

Check what is listening on port 373

Linux: is anything listening on TCP 373?
sudo ss -tlnp 'sport = :373'
Linux: UDP 373
sudo ss -ulnp 'sport = :373'
Linux / macOS: which process owns the port
sudo lsof -nP -i :373
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':373 '
Windows (Command Prompt)
netstat -ano | findstr :373
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 373 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 373
From Windows
Test-NetConnection HOST -Port 373
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 373

Block port 373 in the firewall

ufw
sudo ufw deny 373/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 373 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 373 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 373' -Direction Inbound -Protocol TCP -LocalPort 373 -Action Block
ufw
sudo ufw deny 373/udp
iptables
sudo iptables -A INPUT -p udp --dport 373 -j DROP
nftables
sudo nft add rule inet filter input udp dport 373 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 373' -Direction Inbound -Protocol UDP -LocalPort 373 -Action Block

Related ports

371clearcase372ulistproc374legent-2375hassle

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