Port 9559 (p4runtime)

IANA assigns port 9559 to p4runtime: P4Runtime gRPC Service.

Registered (user) port, 1024-49151 TCP

IANA assignment

Service nameProtoDescriptionAssigneeReference

p4runtime TCP P4Runtime gRPC Service Open Networking Foundation -

Registry dates for this port: registered 2020-09-22.

Linux: is anything listening on TCP 9559?

sudo ss -tlnp 'sport = :9559'

Linux / macOS: which process owns the port

sudo lsof -nP -i :9559

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':9559 '

Windows (Command Prompt)

netstat -ano | findstr :9559

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 9559 -State Listen | Select LocalAddress,OwningProcess

From another machine

nc -vz -w 5 HOST 9559

From Windows

Test-NetConnection HOST -Port 9559

ufw

sudo ufw deny 9559/tcp

iptables

sudo iptables -A INPUT -p tcp --dport 9559 -j DROP

nftables

sudo nft add rule inet filter input tcp dport 9559 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block TCP 9559' -Direction Inbound -Protocol TCP -LocalPort 9559 -Action Block

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