Hi colin5000,
Greetings, when you use the validate knob the device will validate if the existing configuration is compatible with the new image before the actual upgrade or downgrade starts and let you know what is the issue and stop the upgrade if any incompatibilities were found. Using the no-validate the upgrade will succeed but if there are configuration compatibility discrepancies between the old image and new image, the system may not be able to apply the configuration when the system comes up on a newer software image after upgrade and traffic may get impacted until the configuration is corrected and manually committed.
In other words the no-validate' option will bypass most sanity checks, so MUST be used with caution.
NOTE: In case your device is a QFX Please take into consideration that configuration Image Validation is not supported for these platforms during upgrade or downgrade.
It is recommended, to test the compatibility of the configuration prior to the software upgrade on a non-production QFX device.
Regards,
Lil Dexx JNCIE-ENT#863
If this solves your problem, please mark this post as "Accepted Solution" so we can help others too \:)/