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Port 3253 (pda-data)

IANA assigns port 3253 to pda-data: PDA Data.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
pda-data TCP PDA Data - -
pda-data UDP PDA Data - -

Check what is listening on port 3253

Linux: is anything listening on TCP 3253?
sudo ss -tlnp 'sport = :3253'
Linux: UDP 3253
sudo ss -ulnp 'sport = :3253'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3253
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3253 '
Windows (Command Prompt)
netstat -ano | findstr :3253
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3253 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3253
From Windows
Test-NetConnection HOST -Port 3253
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3253

Block port 3253 in the firewall

ufw
sudo ufw deny 3253/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3253 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3253 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3253' -Direction Inbound -Protocol TCP -LocalPort 3253 -Action Block
ufw
sudo ufw deny 3253/udp
iptables
sudo iptables -A INPUT -p udp --dport 3253 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3253 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3253' -Direction Inbound -Protocol UDP -LocalPort 3253 -Action Block

Related ports

3251sysscanner3252dhe3254pda-sys3255semaphore

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