Reference:
user@PA# set deviceconfig system speed-duplex 100Mbps-full-duplex 100Mbps-full-duplex 100Mbps-half-duplex 100Mbps-half-duplex 10Mbps-full-duplex 10Mbps-full-duplex 10Mbps-half-duplex 10Mbps-half-duplex 1Gbps-full-duplex 1Gbps-full-duplex 1Gbps-half-duplex 1Gbps-half-duplex auto-negotiate auto-negotiate

Dynamic user groups help you to create policy that provides auto-remediation for anomalous user behavior and malicious activity while maintaining user visibility. Previously, quarantining users in response to suspicious activity meant time- and resource-consuming updates for all members of the group or updating the IP address-to-username mapping to a label to enforce policy at the cost of user visibility, as well as having to wait until the firewall checked the traffic. Now, you can configure a dynamic user group to automatically include users as members without having to manually create and commit policy or group changes and still maintain user-to-data correlation at the device level before the firewall even scans the traffic.
https://docs.paloaltonetworks.com/pan-os/9-1/pan-os-new-features/user-id-features/dynamic-user-groups.html

From the Palo Alto documentation below, "when a VPN is terminated on a Palo Alto firewall HA pair, not all IPSEC related information is synchronized between the firewalls... This is an expected behavior. IKE phase 1 SA information is NOT synchronized between the HA firewalls." And from the second link, "Data link (HA2) is used to sync sessions, forwarding tables, IPSec security associations, and ARP tables between firewalls in the HA pair. Data flow on the HA2 link is always unidirectional (except for the HA2 keep-alive). It flows from the active firewall to the passive firewall."
https://know
https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA14u000000HAuZCAW ledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA14u000000HAuZCAW&
&lang=en_US%E2%80%A9
lang=en_US%E2%80%A9&
&refURL=http%3A%2F%2Fknowledgebase.palo
refURL=http%3A%2F%2Fknowledgebase.paloaltonetworks.com%2FKCSArticleDetail altonetworks.com%2FKCSArticleDetail
https://help.aryaka.com/display/public/KNOW/Palo+Alto+Networks+NFV+Technical+Brief

Reference:
"Select this option to allow the GlobalProtect agent to determine if it is inside the enterprise network. This option applies only to endpoints that are configured to communicate with internal gateways. When the user attempts to log in, the agent does a reverse DNS lookup of an internal host using the specified Hostname to the specified IP Address. The host serves as a reference point that is reachable if the endpoint is inside the enterprise network. If the agent finds the host, the endpoint is inside the network and the agent connects to an internal gateway; if the agent fails to find the internal host, the endpoint is outside the network and the agent establishes a tunnel to one of the external gateways"