https://devzone.nordicsemi.com/f/nordic-q-a/87245/modem-firmware-reverting-tls-versionDoes the modem firmware revert to using TLSv1 on a failure to connect? I&#39;m getting some occasional weirdness connecting to an OpenSSL based server: It works most of the time but after a while or on a reconnect it fails and doesn&#39;t connect again. en-USTelligent Community 13Mon, 25 Apr 2022 13:46:09 GMThttps://devzone.nordicsemi.com/thread/364748?ContentTypeID=1Mon, 25 Apr 2022 13:46:09 GMT137ad170-7792-4731-bb38-c0d22fbe4515:91e8bfa1-96ac-4124-a7f7-92edef0a6350Jared<p>Hey Charlie,</p> <p>Thanks for the tips. I guess it doesn&#39;t really get much closer to resolution though as I already knew this info. I&#39;ll keep working it on my end.&nbsp;</p> <p>Thanks again</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/364673?ContentTypeID=1Mon, 25 Apr 2022 10:59:36 GMT137ad170-7792-4731-bb38-c0d22fbe4515:0c7ef6d5-08cb-467f-a75f-225187c5f950Charlie<p>Hi Jared,</p> <p>According to&nbsp; <a href="https://www.nordicsemi.com/Products/nRF9160/Download">nRF9160 SiP modem firmware - what it is and how it works</a>:&nbsp;MFW is only &quot;<span>Integrated TLS(1.2)/DTLS(1.2)&quot;.</span></p> <p>Searching keywords&quot;OpenSSL wrong version number&quot; shows this issue seems related to server configuration, can you try the following workaround?</p> <p><a href="https://www.blueskysystems.co.uk/about-us/news-media/ssl3-get-record-wrong-version-number-while-validating-ssl-certificate">SSL3_GET_RECORD:wrong version number&#39; while validating ssl certificate - Blue Sky Systems | Cloud - On-Premise IT</a></p> <p>Best regards,</p> <p>Charlie</p><div style="clear:both;"></div>