- 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 129: Password Generator Protocol
Port 129 is assigned by IANA to pwdgen (Password Generator Protocol).
129
How pwdgen works
Directory & authenticationThe client proves who it is on port 129 and gets an answer (or a ticket) it can use with other services.
- Transport
- TCP · UDP
- 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 129 dangerous?
We have no specific security note for port 129. Its risk depends on the program actually listening on it. General advice for directory & authentication services:
IANA registry entries for port 129
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| pwdgen | 129 | TCP, UDP | Password Generator Protocol | - | - |
// source: IANA service name and port number registry
Which program uses port 129, and is it reachable?
Linux
sudo ss -ltnup 'sport = :129' # process listening on 129
sudo lsof -nP -i :129macOS
sudo lsof -nP -i :129
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 129 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 129 netstat -ano | findstr :129
From another machine
nmap -p 129 -sV <host> sudo nmap -sU -p 129 <host> nc -zv <host> 129
Block it in the firewall
sudo ufw deny 129/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 129" -Direction Inbound -LocalPort 129 -Protocol TCP -Action Block # Windows
What is port 129 used for?
Port 129 is assigned by IANA to pwdgen (Password Generator Protocol).
Is port 129 TCP or UDP?
Port 129 is registered for TCP and UDP.
Is it safe to open port 129?
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 129 is open?
On Linux run "ss -ltnup 'sport = :129'", on macOS "lsof -nP -i :129", and on Windows "netstat -ano | findstr :129" to see the local process. From another machine, "nmap -p 129 <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