This article explains a possible reason why a managed SRX device loses synchronization in Security Director Cloud and provides a solution.

When an SRX device is onboarded to Security Director Cloud, the following configuration is added as part of the adoption process:

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set system services ssh max-sessions-per-connection 20

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If the SRX device was onboarded a long time ago using an older version of Security Director Cloud, this configuration line may not be present in the SRX CLI.

In such cases, the SRX device uses the default value for ssh max-sessions-per-connection, which is 10.

This default setting can impact communication between the SRX device and Security Director Cloud, potentially causing the device to go out of sync.

If this behavior is observed, the user should review the SRX configuration and ensure that ssh max-sessions-per-connection is set to a minimum value of 20, or preferably increased to 32.

If the issue persists even after configuring max-session-per-connection to 32, please flap the connection using the command below to clear the existing netconf channels:

configure

2026-05-06 : Article Created

2026-05-18: SRX adopted in previous SD-Cloud version may not have "max-sessions-per-connection" configuration value