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Port 9300 (Elasticsearch transport)

Node-to-node transport protocol in Elasticsearch clusters.

Registered (user) port, 1024-49151 TCP Databases Do not expose to the internet

What port 9300 is used for

Node-to-node transport protocol in Elasticsearch clusters.

Security: should port 9300 be open?

Do not expose to the internet. Cluster members only; enable transport TLS.

IANA assignment

Service nameProtoDescriptionAssigneeReference
vrace TCP Virtual Racing Service Pete Loeffen -
vrace UDP Virtual Racing Service Pete Loeffen -

Registry dates for this port: registered 2006-10.

Check what is listening on port 9300

Linux: is anything listening on TCP 9300?
sudo ss -tlnp 'sport = :9300'
Linux / macOS: which process owns the port
sudo lsof -nP -i :9300
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':9300 '
Windows (Command Prompt)
netstat -ano | findstr :9300
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 9300 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 9300
From Windows
Test-NetConnection HOST -Port 9300

Block port 9300 in the firewall

ufw
sudo ufw deny 9300/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 9300 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 9300 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 9300' -Direction Inbound -Protocol TCP -LocalPort 9300 -Action Block

Related ports

9200Elasticsearch / OpenSearch HTTP5601Kibana9294armcenterhttp9295armcenterhttps9306sphinxql9310sapms

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