Various techniques for enhanced SASE network processing node (NPN) IPSec high availability are disclosed. In some embodiments, a system, a process, and/or a computer program product for enhanced SASE NPN IPSec high availability includes monitoring a plurality of secure tunnels at an active network processing node (NPN); synchronizing periodically from the active NPN to a standby NPN; and processing each of the plurality of secure tunnels at the standby NPN using a predicted sequence number for an anti-replay sequence window for each of the plurality of secure tunnels after a failover event from the active NPN to the standby NPN, wherein the predicted sequence number for the anti-replay sequence window for each of the plurality of secure tunnels is weighted for a recency bias.