Hi sarahr202,
Your assumption is correct, the reason why is because in step #1
- The master installs the new software image on the backup and reboots it.
By using a pre-provisioned configuration, you will avoid that any of the line-cards replace the back-up RE, while it is rebooting.
If this solves your problem, please mark this post as "Accepted Solution" so we can help others too \:)/
Regards,
Lil Dexx
JNCIE-ENT#863, 3X JNCIP-[SP-ENT-DC], 4X JNCIA [cloud-DevOps-Junos-Design], Champions Ingenius, SSYB