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Port 3948 (apdap)

IANA assigns port 3948 to apdap: Anton Paar Device Administration Protocol.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
apdap TCP Anton Paar Device Administration Protocol Martin Leitner -
apdap UDP Anton Paar Device Administration Protocol Martin Leitner -

Registry dates for this port: registered 2004-06.

Check what is listening on port 3948

Linux: is anything listening on TCP 3948?
sudo ss -tlnp 'sport = :3948'
Linux: UDP 3948
sudo ss -ulnp 'sport = :3948'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3948
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3948 '
Windows (Command Prompt)
netstat -ano | findstr :3948
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3948 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3948
From Windows
Test-NetConnection HOST -Port 3948
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3948

Block port 3948 in the firewall

ufw
sudo ufw deny 3948/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3948 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3948 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3948' -Direction Inbound -Protocol TCP -LocalPort 3948 -Action Block
ufw
sudo ufw deny 3948/udp
iptables
sudo iptables -A INPUT -p udp --dport 3948 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3948 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3948' -Direction Inbound -Protocol UDP -LocalPort 3948 -Action Block

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Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.