When a Switch Control Board SRX5K (SCB3) is installed in the chassis and the Routing Engine (RE) is replaced (RMA), the new RE may come with a version 12.3X48 or lower software release, and the system will not boot successfully.
After replacing the RE in the SRX5000 Series chassis (for example, after RMA), the system does not boot properly. Junos boots up, but certain CLI commands do not work, the FPCs do not boot up, and the system is not operational.
A new chassis with version 15.1X49 software typically has one or more SCB3 cards installed. If the RE crashes and needs to be replaced, it can run the following software releases: 12.1X47, 12.3X48 and 15.1X49. The SCB3 card only supports 15.1X49 and later. For more information, refer to Switch Control Board SRX5K-SCB3 Specifications . If the RE comes with a software release lower than 15.1X49, it will not recognize the SCB3 and the system will not boot properly. There are two steps to identify if you are experiencing this issue:
Notice the software release when the RE booted:
Amnesiac (ttyd0) login: root --- JUNOS 12.1X47-D15.4 built 2014-11-12 01:42:12 UTC
Look for the following messages in the boot process:
ERROR: routing engine slot identification failed ERROR: ACB FPGA not configured Initializing product: 0 ..
In order to recover the system, a new software installation is needed. The correct software release is 15.1X49 and the install media procedure must be performed. Take the following steps:
Download the correct Install Media file that you want to install.
Copy it to a memory stick and insert it into the RE in the USB slot 0
Use the procedure in KB15178 - Using USB storage in SRX series when upgrading JUNOS Software [juniper.net] to copy it to /var/tmp
Once the file is copied there, leave the memory stick inside. It will be used as a recovery mechanism in the next step
Use KB19576 - [SRX] How to prepare an Emergency USB Boot Disk with install-media file for high-end SRX [juniper.net] to recover the RE
If this procedure does not resolve the issue, please contact JTAC for further assistance.
2020-10-07: Article reviewed for accuracy. No changes required.