How do VPN statistics work

1. Each Defguard gateway reads kernel data from the WireGuard® interface for each peer.

2. If any change is detected between previous stats (bytes in/out) then through the gRPC interface the gateway sends those statistics to Defguard core.

If the gateway doesn't detect any changes in stats, doesn't send anything to core.

The period for each gateway to gather stats from the interfaces is defined by DEFGUARD_STATS_PERIOD ENV value (or -p argument) - default 30sec.

1. Core stores all the data send trough gRPC in the database (table wireguard_peer_stats).

2. Then when displaying the VPN overview does all the calculations and aggregations of the data to display them.