Palo Alto AD Server Synch Troubleshooting

To verify the connectivity and synchronization status of your Active Directory (AD) servers on a Palo Alto Networks firewall, you would typically use the following CLI (Command Line Interface) command:

show user server-monitor state all

This command shows the state of all configured User-ID agents and monitored servers. It will display each server’s connection and synchronization status. For Active Directory, you’ll see the name or IP address of the server, the connection status, whether or not the connection is currently up, and the time the last sync occurred.

If you want to see the status of a specific server, replace ‘all’ with the name of the server you’re interested in:

show user server-monitor state {ServerName}

Please note that these commands may vary depending on your Palo Alto Networks firewall’s configuration and version. Always refer to the official Palo Alto Networks documentation or your firewall’s online help for the most accurate and up-to-date information.

One more useful command you can use:

show user server-monitor statistics



If a Palo Alto firewall has connectivity issues with a few of the listed servers, especially Active Directory (AD) servers, several issues can arise:

1. User Identification: If the firewall loses connectivity to AD servers, it can lose its ability to accurately map IP addresses to usernames (User-ID). This loss would affect policies based on User-ID, possibly leading to unauthorized access or unnecessary blocks.

2. Group-based Policies: Policies based on AD groups would also be affected, as the firewall might not be able to pull the latest group information from AD servers. This issue could lead to similar access problems.

3. Authentication: For services requiring user authentication (like GlobalProtect VPN or Captive Portal), the firewall needs to reach the AD servers to verify credentials. If connectivity is lost, users might not be able to authenticate and access the network resources.

4. Security Events Monitoring: If User-ID information is shared with other components of the network security infrastructure (e.g., SIEM systems), the loss of accurate user mapping information could make monitoring and incident response activities more difficult.

5. Redundancy and Performance: If multiple servers are listed for redundancy and load balancing, having some of them unreachable can put additional load on the remaining servers and potentially affect their performance.

6. SSL Decryption: If the firewall uses an AD server for SSL decryption broker, losing connectivity can impact SSL decryption.

In the event of server connectivity issues, it’s essential to troubleshoot and restore the connections as soon as possible to ensure the firewall continues to provide robust network security.



In the context of a Palo Alto Networks firewall, when there’s a list of servers configured for the User-ID agent to monitor (like Active Directory servers), the firewall processes them in the order in which they are listed.

If the first server in the list is available, the firewall will connect to it and begin pulling User-ID information. If that server becomes unreachable, the firewall will attempt to connect to the next server in the list, and so forth. This process is done to provide redundancy and ensure that the firewall can continue to pull User-ID information even if one or more servers become unreachable.

However, starting from PAN-OS 9.0, there’s a feature called “Distribution of User-ID information collection” which allows User-ID to distribute the load of information collection across all available servers instead of the traditional sequential method.

Remember, it’s always a good idea to refer to the official Palo Alto Networks documentation or your firewall’s online help for the most accurate and up-to-date information, as capabilities can change between different versions of the firewall software.