A Zero Downtime Upgrade of a cluster:
A.
Upgrades all cluster members except one at the same time.
B.
Is only supported in major releases (R70 to R71, R71 to R77).
C.
Requires breaking the cluster and upgrading members independently.
D.
Treats each individual cluster member as an individual gateway.
A –
One member remains active to ensure no downtime
A sk107042
A. Upgrades all cluster members except one at the same time.
https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk107042
Zero Downtime:
During this type of upgrade, there is always at least one Active cluster member that handles the traffic. Connections are not synchronized between cluster members running different Check Point software versions.