Network Activity
Displays an overview of traffic and user activity on your network including:
Top applications in use
Top users who generate traffic (with a drill down into the bytes, content, threats or URLs accessed by the user) Most used security rules against which traffic matches occur In addition, you can also view network activity by source or destination zone, region, or IP address, ingress or egress interfaces, and GlobalProtect host information such as the operating systems of the devices most commonly used on the network.

To set up high availability on your Palo Alto Networks firewalls, you need a pair of firewalls that meet the following requirements:
The same set of licenses --Licenses are unique to each firewall and cannot be shared between the firewalls. Therefore, you must license both firewalls identically. If both firewalls do not have an identical set of licenses, they cannot synchronize configuration information and maintain parity for a seamless failover.
The same type of interfaces --Dedicated HA links, or a combination of the management port and in-band ports that are set to interface type HA.
Determine the IP address for the HA1 (control) connection between the HA peers. The HA1 IP address for both peers must be on the same subnet if they are directly connected or are connected to the same switch.
Etc.

* Ping Interval-Specify the interval between pings that are sent to the destination IP address (range is 200 to 60,000ms; default is 200ms).
* Ping Count-Specify the number of failed pings before declaring a failure (range is 3 to 10; default is 10).

Explanation:
Reference: https://docs.paloaltonetworks.com/panorama/9-1/panorama-admin/manage- firewalls/set-up-zero-touch-provisioning/ztp-overview/ztp-configuration-elements.html

https://docs.paloaltonetworks.com/pan-os/10-1/pan-os-admin/decryption/troubleshoot-and- monitor-decryption/decryption-troubleshooting-workflow-examples/troubleshoot-certificate- expiration-issues