- Keep directory and authentication services on internal networks.
- Require signing or TLS and disable anonymous queries.
- Monitor authentication failures for spraying and brute force.
Port 323: Resource PKI to Router Protocol
Port 323 is assigned by IANA to rpki-rtr (Resource PKI to Router Protocol).
323
How rpki-rtr works
Directory & authenticationThe client proves who it is on port 323 and gets an answer (or a ticket) it can use with other services.
- Transport
- TCP
- Exposure risk
- not rated depends on the program listening
- Encryption
- Unknownnot stated by the registry
- IANA status
- Assigned1 registered service
- Range
- Well-known (0-1023)
- Category
- Directory & authentication
Is port 323 dangerous?
We have no specific security note for port 323. Its risk depends on the program actually listening on it. General advice for directory & authentication services:
IANA registry entries for port 323
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| rpki-rtr | 323 | TCP | Resource PKI to Router Protocol | RFC 6810 | - |
| - | 323 | - | Reserved | - | - |
// source: IANA service name and port number registry
Which program uses port 323, and is it reachable?
Linux
sudo ss -ltnup 'sport = :323' # process listening on 323
sudo lsof -nP -i :323macOS
sudo lsof -nP -i :323
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 323 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 323 netstat -ano | findstr :323
From another machine
nmap -p 323 -sV <host> nc -zv <host> 323
Block it in the firewall
sudo ufw deny 323/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 323" -Direction Inbound -LocalPort 323 -Protocol TCP -Action Block # Windows
What is port 323 used for?
Port 323 is assigned by IANA to rpki-rtr (Resource PKI to Router Protocol).
Is port 323 TCP or UDP?
Port 323 is registered for TCP.
Is it safe to open port 323?
It depends on the program that listens on it. Open it only for a service you know and only to the networks that need it. Keep directory and authentication services on internal networks.
How do I check if port 323 is open?
On Linux run "ss -ltnup 'sport = :323'", on macOS "lsof -nP -i :323", and on Windows "netstat -ano | findstr :323" to see the local process. From another machine, "nmap -p 323 <host>" shows whether it is reachable.
Other directory & authentication ports
:389 LDAP tcp · udp · high risk :636 LDAPS tcp · udp · moderate risk :88 Kerberos tcp · udp · high risk :3268 Global Catalog (LDAP) tcp · udp · high risk :1812 RADIUS udp · tcp · moderate risk :31 MSG Authentication tcp · udp :49 Login Host Protocol (TACACS) tcp · udp :56 XNS Authentication tcp · udp