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Port 344 (pdap)

IANA assigns port 344 to pdap: Prospero Data Access Protocol.

Well-known (system) port, 0-1023 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
pdap TCP Prospero Data Access Protocol B Clifford Neuman -
pdap UDP Prospero Data Access Protocol B Clifford Neuman -

Check what is listening on port 344

Linux: is anything listening on TCP 344?
sudo ss -tlnp 'sport = :344'
Linux: UDP 344
sudo ss -ulnp 'sport = :344'
Linux / macOS: which process owns the port
sudo lsof -nP -i :344
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':344 '
Windows (Command Prompt)
netstat -ano | findstr :344
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 344 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 344
From Windows
Test-NetConnection HOST -Port 344
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 344

Block port 344 in the firewall

ufw
sudo ufw deny 344/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 344 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 344 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 344' -Direction Inbound -Protocol TCP -LocalPort 344 -Action Block
ufw
sudo ufw deny 344/udp
iptables
sudo iptables -A INPUT -p udp --dport 344 -j DROP
nftables
sudo nft add rule inet filter input udp dport 344 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 344' -Direction Inbound -Protocol UDP -LocalPort 344 -Action Block

Related ports

324rpki-rtr-tls333texar345pawserv346zserv

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