HTTPfy

Port 3748 (webdata)

IANA assigns port 3748 to webdata: webData.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
webdata TCP webData Michael Whiteley -
webdata UDP webData Michael Whiteley -

Registry dates for this port: registered 2003-04.

Check what is listening on port 3748

Linux: is anything listening on TCP 3748?
sudo ss -tlnp 'sport = :3748'
Linux: UDP 3748
sudo ss -ulnp 'sport = :3748'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3748
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3748 '
Windows (Command Prompt)
netstat -ano | findstr :3748
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3748 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3748
From Windows
Test-NetConnection HOST -Port 3748
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3748

Block port 3748 in the firewall

ufw
sudo ufw deny 3748/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3748 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3748 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3748' -Direction Inbound -Protocol TCP -LocalPort 3748 -Action Block
ufw
sudo ufw deny 3748/udp
iptables
sudo iptables -A INPUT -p udp --dport 3748 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3748 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3748' -Direction Inbound -Protocol UDP -LocalPort 3748 -Action Block

Related ports

3746linktest3747linktest-s3749cimtrak3750cbos-ip-port

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