This article will help you to understand why Resynchronize-with-network job is failing and provides 

1. Device will go in "out of sync" state.

2. "Resynchronize with network" job will fail with below error 

Reason: Sync Inventory : hardware - failed to discover resource - rpc error: code = Unavailable desc = last connection error: connection closed interface - failed to discover resource - rpc error: code = Unavailable desc = last connection error: connection closed software - failed to discover resource - rpc error: code = Unavailable desc = last connection error: connection closed license - failed to discover resource - rpc error: code = Unavailable desc = last connection error: connection closed system - failed to discover resource - rpc error: code = Unavailable desc = last connection error: connection closed configuration - failed to discover resource - rpc error: code = Unavailable desc = last connection error: connection closed certificate - failed to discover resource - rpc error: code = Unavailable desc = last connection error: connection closed cacertificate - failed to discover resource - rpc error: code = Unavailable desc = last connection error: connection closed

#Root Cause Analysis:

"Resync with network" Job will fail with mentioned error incase if device is unable to connect SD Cloud on port 7804.

Step 1: We need to troubleshoot the issue from device end to understand the connection issue on port 7804, below two command can help you to understand the device connection issue on port 7804

> show security flow session destination-port 7804

> telnet srx.sdcloud.juniperclouds.net port 7804

Step 2: Once device connection issue on port 7804 is resolved then follow below steps to Resync the device.

SD Cloud UI -> SRX -> Device Management -> Select the affected Device -> under more -> select Resync with network -> Job will be triggered for the same -> Make sure the Job is success.

Note : If you face any issues, please contact JUNIPER JTAC Support for assistance.