SLM XFOTA always fails

[Bernhard]

Hello,

we are trying to perform FOTA updates with default SLM application based on SDK 2.9.0,
but the application always aborts unsuccessfully.

Via AT interface the application responds:

    XFOTA.fota_stage= 0 -> Init
    XFOTA.fota_status= 1 -> Error
    XFOTA.fota_info= 2 -> Update image rejected

Via RTT-Logging there is an error "DNS lookup failed"

I have made some small overlays only to get the correct UART pins, but havent changed the application besides that.
For another nRF9160 application (not based on SLM / XFOTA commands) the FOTA update with this server is working fine.

I made a modem trace of one XFOTA attempt:

trace-2025-03-08T16-56-02.721Z.mtrace

Would appreciate any hint to get it running.

Thank you and best regards,
Bernhard

[Bernhard]

Hello,

this is the full output:

00> *** Booting nRF Connect SDK v2.9.0-7787b2649840 ***
00> *** Using Zephyr OS v3.7.99-1f8f3dc29142 ***
00> [00:00:00.255,706] <inf> at_cmd_custom: Custom AT commands enabled with 41 entries.
00> [00:00:00.261,901] <inf> fs_nvs: 2 Sectors of 4096 bytes
00> [00:00:00.261,932] <inf> fs_nvs: alloc wra: 0, fe8
00> [00:00:00.261,932] <inf> fs_nvs: data wra: 0, 0
00> [00:00:00.493,988] <inf> nrf_modem_lib_trace: Trace thread ready
00> [00:00:00.501,464] <inf> nrf_modem_lib_trace: Trace level override: 2
00> [00:00:00.502,471] <inf> slm: lib_modem init: 0
00> [00:00:00.503,021] <inf> mcuboot_util: Image index: 0, Swap type: none
00> [00:00:00.503,051] <inf> slm: Serial LTE Modem
00> [00:00:00.597,015] <inf> nrf_cloud_info: Device ID: 504b5839-3736-4e69-8022-202375aab4b4
00> [00:00:00.602,447] <inf> nrf_cloud_info: IMEI:      350457794629749
00> [00:00:00.695,312] <inf> nrf_cloud_info: UUID:      504b5839-3736-4e69-8022-202375aab4b4
00> [00:00:00.701,08MQTT
00> 
00> [00:00:22.069,091] <inf> slm_ppp: Connection up. Starting PPP.
00> [00:00:22.072,265] <inf> slm_ppp: PPP started.
00> [00:01:08.481,658] <inf> download_client: Downloading: terminal-modem/delta_1.3.7_to_1.3.7-FOTA-TEST/modem.bin [0]
00> [00:02:08.506,683] <err> download_client: DNS lookup failed http://embacher.pythonanywhere.com
00> [00:02:08.506,744] <err> fota_download: Download client error

[Sigurd]

Does it help to set these in prj.conf?

CONFIG_DNS_RESOLVER=y
CONFIG_DNS_SERVER_IP_ADDRESSES=y
CONFIG_DNS_SERVER1="8.8.8.8"

[Bernhard]

Hello,

I have tried these configurations already but (although I cann see changes in the generated .config and .hex files) they are not functional at all. Not only is the result of the XFOTA command the same but also "AT+CGCONTRDP=0" still responds with the old DNS address in "DNS_prim_addr" and also in the pppd logfile there is still the original DNS configured.

Best regards,
Bernhard

[Sigurd]

Hi!

Could you check if it works when you set CONFIG_SLM_PPP=n