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Port 10259 (kube-scheduler)

Secure metrics and health endpoint of kube-scheduler.

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

What port 10259 is used for

Secure metrics and health endpoint of kube-scheduler.

Security: should port 10259 be open?

Do not expose to the internet. Control-plane only.

IANA assignment

Port 10259 is in the registered range and has no IANA assignment. The usage above is unofficial but widespread.

Check what is listening on port 10259

Linux: is anything listening on TCP 10259?
sudo ss -tlnp 'sport = :10259'
Linux / macOS: which process owns the port
sudo lsof -nP -i :10259
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':10259 '
Windows (Command Prompt)
netstat -ano | findstr :10259
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 10259 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 10259
From Windows
Test-NetConnection HOST -Port 10259

Block port 10259 in the firewall

ufw
sudo ufw deny 10259/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 10259 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 10259 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 10259' -Direction Inbound -Protocol TCP -LocalPort 10259 -Action Block

Related ports

10257kube-controller-manager6443Kubernetes API server10252apollo-relay10253eapol-relay10260axis-wimp-port10261tile-ml10288blocks

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