About Discovery enabled explain:
When enabled (and LoRa App Server is configured with the gateway discover feature enabled), the gateway will send out periodical pings to test its coverage by other gateways in the same network.
in source i find.there is lora-app-server/loraserver send out periodical pings.
Is there a problem?
I’m not sure if I understand your question or problem? LoRa App Server schedules the discovery “ping” and requests the gateway to transmit this.
Sorry,my english is very poor.
i means:
in help, the gateway will send out periodical pings to test its coverage by other gateways in the same network.
in source code is LoRa App Server schedules the discovery “ping” and send to gateways.
1.“Pings” is sent by gateway or by Lora App Server?
I tested the following questions.
The pings sent by Lora App Server can only be sent to this gateway, and cannot be broadcast to other gateways.
So Lora App Server does not receive ping_rx from other gateways.
lora-gateway-bridge send udp packet to gateway
LoRa App Server schedules the ping, and through LoRa Server the gateway sends it 
Thank you for your reply.
In addition, I tested the findings.
LoRa App Server sends PINGS to send only the current gateway, not to other gateways.
The reply to the current gateway will not be logged to the database.