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Port 23003 (inovaport4)

IANA assigns port 23003 to inovaport4: Inova LightLink Server Type 4.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
inovaport4 TCP Inova LightLink Server Type 4 Chris Koeritz 3 -
inovaport4 UDP Inova LightLink Server Type 4 Chris Koeritz 3 -

Registry dates for this port: registered 2006-10.

Check what is listening on port 23003

Linux: is anything listening on TCP 23003?
sudo ss -tlnp 'sport = :23003'
Linux: UDP 23003
sudo ss -ulnp 'sport = :23003'
Linux / macOS: which process owns the port
sudo lsof -nP -i :23003
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':23003 '
Windows (Command Prompt)
netstat -ano | findstr :23003
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 23003 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 23003
From Windows
Test-NetConnection HOST -Port 23003
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 23003

Block port 23003 in the firewall

ufw
sudo ufw deny 23003/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 23003 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 23003 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 23003' -Direction Inbound -Protocol TCP -LocalPort 23003 -Action Block
ufw
sudo ufw deny 23003/udp
iptables
sudo iptables -A INPUT -p udp --dport 23003 -j DROP
nftables
sudo nft add rule inet filter input udp dport 23003 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 23003' -Direction Inbound -Protocol UDP -LocalPort 23003 -Action Block

Related ports

23001inovaport223002inovaport323004inovaport523005inovaport6

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