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Port 380 (is99s)

IANA assigns port 380 to is99s: TIA/EIA/IS-99 modem server.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
is99s TCP TIA/EIA/IS-99 modem server Frank Quick -
is99s UDP TIA/EIA/IS-99 modem server Frank Quick -

Check what is listening on port 380

Linux: is anything listening on TCP 380?
sudo ss -tlnp 'sport = :380'
Linux: UDP 380
sudo ss -ulnp 'sport = :380'
Linux / macOS: which process owns the port
sudo lsof -nP -i :380
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':380 '
Windows (Command Prompt)
netstat -ano | findstr :380
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 380 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 380
From Windows
Test-NetConnection HOST -Port 380
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 380

Block port 380 in the firewall

ufw
sudo ufw deny 380/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 380 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 380 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 380' -Direction Inbound -Protocol TCP -LocalPort 380 -Action Block
ufw
sudo ufw deny 380/udp
iptables
sudo iptables -A INPUT -p udp --dport 380 -j DROP
nftables
sudo nft add rule inet filter input udp dport 380 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 380' -Direction Inbound -Protocol UDP -LocalPort 380 -Action Block

Related ports

378dsETOS379is99c381hp-collector382hp-managed-node

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