Hello, I'm facing an issue while using Atlas API. Some connections (not all) to https://atlas.ripe.net fail because of what seems to be an invalid certs chain. It looks like that an intermediate cert is missing. SSLLabs too reports something similar: https://www.ssllabs.com/ssltest/analyze.html?d=atlas.ripe.net&s=193.0.6.158 $ openssl s_client -connect atlas.ripe.net:443 -servername atlas.ripe.net CONNECTED(00000003) depth=0 C = NL, ST = Noord-Holland, L = Amsterdam, O = RIPE NCC, CN = atlas.ripe.net verify error:num=20:unable to get local issuer certificate verify return:1 depth=0 C = NL, ST = Noord-Holland, L = Amsterdam, O = RIPE NCC, CN = atlas.ripe.net verify error:num=27:certificate not trusted verify return:1 depth=0 C = NL, ST = Noord-Holland, L = Amsterdam, O = RIPE NCC, CN = atlas.ripe.net verify error:num=21:unable to verify the first certificate verify return:1 --- Certificate chain 0 s:/C=NL/ST=Noord-Holland/L=Amsterdam/O=RIPE NCC/CN=atlas.ripe.net i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 High Assurance Server CA --- Server certificate -----BEGIN CERTIFICATE----- ... -----END CERTIFICATE----- subject=/C=NL/ST=Noord-Holland/L=Amsterdam/O=RIPE NCC/CN=atlas.ripe.net issuer=/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 High Assurance Server CA --- ... Verify return code: 21 (unable to verify the first certificate) -- Pier Carlo Chiodi - Active Network S.p.A. via della Chimica, 18 - 01100 Viterbo Tel: +39 0761 17691 08 - Fax: +39 06 23328079