HTTPfy

Port 381 (hp-collector)

IANA assigns port 381 to hp-collector: hp performance data collector.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
hp-collector TCP hp performance data collector - -
hp-collector UDP hp performance data collector - -

Check what is listening on port 381

Linux: is anything listening on TCP 381?
sudo ss -tlnp 'sport = :381'
Linux: UDP 381
sudo ss -ulnp 'sport = :381'
Linux / macOS: which process owns the port
sudo lsof -nP -i :381
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':381 '
Windows (Command Prompt)
netstat -ano | findstr :381
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 381 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 381
From Windows
Test-NetConnection HOST -Port 381
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 381

Block port 381 in the firewall

ufw
sudo ufw deny 381/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 381 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 381 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 381' -Direction Inbound -Protocol TCP -LocalPort 381 -Action Block
ufw
sudo ufw deny 381/udp
iptables
sudo iptables -A INPUT -p udp --dport 381 -j DROP
nftables
sudo nft add rule inet filter input udp dport 381 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 381' -Direction Inbound -Protocol UDP -LocalPort 381 -Action Block

Related ports

379is99c380is99s382hp-managed-node383hp-alarm-mgr

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