nRF9160 SICA B1: DNS resolution issue

[bim]

Hello Community,

I am trying to test mqtt_simple sample on both of nRF9160-DK(nRF9160 SICA B1) and Thingy91(nRF9160 SICA B0).

My hardware version:
nRF9160-DK: 1.0.0
Thingy91: 1.4.0

Thingy91 can get the IPv4 address by getaddrinfo but nRF9160-DK couldn't.

[00:00:06.842,926] <inf> mqtt_simple: LTE Link Connected!
[00:00:06.843,170] <err> mqtt_simple: getaddrinfo failed: -11
[00:00:06.843,170] <err> mqtt_simple: Failed to initialize broker connection
[00:00:06.843,170] <err> mqtt_simple: client_init: -10

The modem firmware version is v1.3.1 on both of them. I tried to upgrade to v1.3.2 on nRF9160 SICA B1 but it doesn't help. Also I checked it on both of Thingy91 and DK using same SIM card (NB-IoT) so no issues from the provider.

I could see DNS servers on thingy91.

AT+CGCONTRDP=0
+CGCONTRDP: 0,,"CMNBIOT2","","","211.136.17.107","211.136.20.203"
+CGCONTRDP: 0,,"CMNBIOT2","","","2409:8080:0000:0000:0000:0000:0000:0001","2409:8080:0000:0000:0000:0000:0000:0002"

But not on nRF9160-DK

AT+CGCONTRDP=0
+CGCONTRDP: 0,,"CMNBIOT2","",""

I thought it might be related to nRF9160 SiP revision and modem firmware version but no luck.

I took a look at the similar issues and this helps but it's not preferred way.

Thanks.

[bim]

I found a pretty old nRF9160-DK(hardware version: 0.8.3, NRF9160_SICA_BA) and it works though.
Its modem firmware version:

AT+CGMR
mfw_nrf9160_1.2.3

Hopefully it might be helpful for someone to figure out the reason.

[Hakon]

Did you use the same SIM card as before? Have you tried the 1.2.3 firmware on the newer DK?

[bim]

Yes, it's same SIM card.

Hakon said:

Have you tried the 1.2.3 firmware on the newer DK?

I tried modem firmware v1.2.3 but it's still failing for getaddrinfo with -11.

[Hakon]

Can you do a modem trace? Follow these instructions to get a raw trace.