Port 323 (rpki-rtr)

IANA assigns port 323 to rpki-rtr: Resource PKI to Router Protocol.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference

rpki-rtr TCP Resource PKI to Router Protocol IESG RFC 6810

Linux: is anything listening on TCP 323?

sudo ss -tlnp 'sport = :323'

Linux / macOS: which process owns the port

sudo lsof -nP -i :323

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':323 '

Windows (Command Prompt)

netstat -ano | findstr :323

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 323 -State Listen | Select LocalAddress,OwningProcess

From another machine

nc -vz -w 5 HOST 323

From Windows

Test-NetConnection HOST -Port 323

ufw

sudo ufw deny 323/tcp

iptables

sudo iptables -A INPUT -p tcp --dport 323 -j DROP

nftables

sudo nft add rule inet filter input tcp dport 323 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block TCP 323' -Direction Inbound -Protocol TCP -LocalPort 323 -Action Block

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