Hi @Ping
For a DNS lookup, it is important to set the following config items:
#define ipconfigDNS_RECEIVE_BLOCK_TIME_TICKS pdMS_TO_TICKS( 2500U )
#define ipconfigDNS_SEND_BLOCK_TIME_TICKS pdMS_TO_TICKS( 2500U )
This example puts them to 2.5 seconds, but you may choose a longer period.
If these values are not defined , the default values are :
#define ipconfigDNS_RECEIVE_BLOCK_TIME_TICKS pdMS_TO_TICKS( 5000U )
#define ipconfigDNS_SEND_BLOCK_TIME_TICKS pdMS_TO_TICKS( 500U )
You can also look at this topic for more reference.