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Port 388 (unidata-ldm)

IANA assigns port 388 to unidata-ldm: Unidata LDM.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
unidata-ldm TCP Unidata LDM University Corporation for Atmospheric Research2 -
unidata-ldm UDP Unidata LDM University Corporation for Atmospheric Research2 -

Registry dates for this port: last modified 2012-05-18.

Check what is listening on port 388

Linux: is anything listening on TCP 388?
sudo ss -tlnp 'sport = :388'
Linux: UDP 388
sudo ss -ulnp 'sport = :388'
Linux / macOS: which process owns the port
sudo lsof -nP -i :388
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':388 '
Windows (Command Prompt)
netstat -ano | findstr :388
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 388 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 388
From Windows
Test-NetConnection HOST -Port 388
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 388

Block port 388 in the firewall

ufw
sudo ufw deny 388/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 388 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 388 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 388' -Direction Inbound -Protocol TCP -LocalPort 388 -Action Block
ufw
sudo ufw deny 388/udp
iptables
sudo iptables -A INPUT -p udp --dport 388 -j DROP
nftables
sudo nft add rule inet filter input udp dport 388 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 388' -Direction Inbound -Protocol UDP -LocalPort 388 -Action Block

Related ports

386asa387aurp389LDAP390uis

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