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Port 371 (clearcase)

IANA assigns port 371 to clearcase: Clearcase.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
clearcase TCP Clearcase Dave LeBlang -
clearcase UDP Clearcase Dave LeBlang -

Check what is listening on port 371

Linux: is anything listening on TCP 371?
sudo ss -tlnp 'sport = :371'
Linux: UDP 371
sudo ss -ulnp 'sport = :371'
Linux / macOS: which process owns the port
sudo lsof -nP -i :371
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':371 '
Windows (Command Prompt)
netstat -ano | findstr :371
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 371 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 371
From Windows
Test-NetConnection HOST -Port 371
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 371

Block port 371 in the firewall

ufw
sudo ufw deny 371/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 371 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 371 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 371' -Direction Inbound -Protocol TCP -LocalPort 371 -Action Block
ufw
sudo ufw deny 371/udp
iptables
sudo iptables -A INPUT -p udp --dport 371 -j DROP
nftables
sudo nft add rule inet filter input udp dport 371 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 371' -Direction Inbound -Protocol UDP -LocalPort 371 -Action Block

Related ports

369rpc2portmap370codaauth2372ulistproc373legent-1

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