Q: If DNS requests are failing, it seems like that is depending on network congestion or DNS server response timeout.
A: By default, the DNS servers are delivered by the SIM provider (APN settings).
These DNS settings can be tested and changed and are stored into the Modem.
Modem access is available using the COM port terminal, option [M]
T: Connect to the data logger. Go into Maintenance menu, select , COM port terminal and choose [M], Modem.
The modem will be powered up, and available for testing.
Verify or configure the DNS servers, that can only be done with modem power ON and NO connection to the Internet:
To verify the configured DNS servers, connect to the Internet and test your <fqdn> to resolve:
To check which DNS servers are active, use AT#NWDNS=1, when connected to the Internet: