Juniper SRX upgrade via SD Cloud - FAQ's

• How do we know if the upgrade process would use ICU or ISSU? Would we choose this, or would SD Cloud choose which method is more suitable?

SD-Cloud will automatically choose an upgrade method based on the device model. Almost all high-end SRTs uses ISSU, and VSRX doesn't support ISSU. If the device supports ISSU, then automatically ISSU upgrade is triggered.

• The Guide does not mention what to expect during the upgrade process.

You will see the job progress in Sd-Cloud jobs page.

• Do we expect any downtime during ISSU upgrade?

If the upgrade process is ISSU then it eliminates network downtime during the process.

• Would the reboot happen at the same time?

The process is explained in detail here

• What would happen if the upgrade fails? Would traffic still be forwarding?

You will see a failed job in the SD cloud and a reason for the failure. If the upgrade process is ISSU then it eliminates network downtime during the process.

• What checks can we do after the firewall upgrade?

The devices are automatically rebooted after the image is upgraded. Juniper Security Director Cloud synchronizes with the device after the device connects back. If the version is not upgraded, the job would fail. From the device side, you can check if all configurations are working fine.

• Does all SRX modes supports ISSU?

List of supported devices here - url