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Port 3803 (soniqsync)

IANA assigns port 3803 to soniqsync: SoniqSync.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
soniqsync TCP SoniqSync Ryan Melville -
soniqsync UDP SoniqSync Ryan Melville -

Registry dates for this port: registered 2004-01.

Check what is listening on port 3803

Linux: is anything listening on TCP 3803?
sudo ss -tlnp 'sport = :3803'
Linux: UDP 3803
sudo ss -ulnp 'sport = :3803'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3803
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3803 '
Windows (Command Prompt)
netstat -ano | findstr :3803
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3803 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3803
From Windows
Test-NetConnection HOST -Port 3803
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3803

Block port 3803 in the firewall

ufw
sudo ufw deny 3803/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3803 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3803 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3803' -Direction Inbound -Protocol TCP -LocalPort 3803 -Action Block
ufw
sudo ufw deny 3803/udp
iptables
sudo iptables -A INPUT -p udp --dport 3803 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3803 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3803' -Direction Inbound -Protocol UDP -LocalPort 3803 -Action Block

Related ports

3801ibm-mgr3802vhd3804iqnet-port3805tcpdataserver

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