Port 9200 (Elasticsearch / OpenSearch HTTP)

Elasticsearch and OpenSearch REST API.

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

What port 9200 is used for

Elasticsearch and OpenSearch REST API.

Security: should port 9200 be open?

Do not expose to the internet. Exposed Elasticsearch clusters are one of the biggest sources of data leaks; old versions had no authentication by default. Elasticsearch 8 enables security by default; keep it on, bind to private addresses and put Kibana or your app in front.

IANA assignment

Service nameProtoDescriptionAssigneeReference

wap-wsp TCP WAP connectionless session service WAP Forum -

wap-wsp UDP WAP connectionless session service WAP Forum -

Check what is listening on port 9200

Linux: is anything listening on TCP 9200?

sudo ss -tlnp 'sport = :9200'

Linux / macOS: which process owns the port

sudo lsof -nP -i :9200

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':9200 '

Windows (Command Prompt)

netstat -ano | findstr :9200

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 9200 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine

nc -vz -w 5 HOST 9200

From Windows

Test-NetConnection HOST -Port 9200

Block port 9200 in the firewall

ufw

sudo ufw deny 9200/tcp

iptables

sudo iptables -A INPUT -p tcp --dport 9200 -j DROP

nftables

sudo nft add rule inet filter input tcp dport 9200 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block TCP 9200' -Direction Inbound -Protocol TCP -LocalPort 9200 -Action Block

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Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.