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Port 4403 (ds-user)

IANA assigns port 4403 to ds-user: ASIGRA Televaulting DS-Client Monitoring/Management.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
ds-user TCP ASIGRA Televaulting DS-Client Monitoring/Management - -
ds-user UDP ASIGRA Televaulting DS-Client Monitoring/Management - -

Check what is listening on port 4403

Linux: is anything listening on TCP 4403?
sudo ss -tlnp 'sport = :4403'
Linux: UDP 4403
sudo ss -ulnp 'sport = :4403'
Linux / macOS: which process owns the port
sudo lsof -nP -i :4403
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':4403 '
Windows (Command Prompt)
netstat -ano | findstr :4403
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4403 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 4403
From Windows
Test-NetConnection HOST -Port 4403
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 4403

Block port 4403 in the firewall

ufw
sudo ufw deny 4403/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 4403 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 4403 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 4403' -Direction Inbound -Protocol TCP -LocalPort 4403 -Action Block
ufw
sudo ufw deny 4403/udp
iptables
sudo iptables -A INPUT -p udp --dport 4403 -j DROP
nftables
sudo nft add rule inet filter input udp dport 4403 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 4403' -Direction Inbound -Protocol UDP -LocalPort 4403 -Action Block

Related ports

4401ds-srvr4402ds-clnt4404ds-admin4405ds-mail

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