We found the version of curl provided for RHEL5 does not include the flags "--tlsv1.1" or "--tlsv1.2" provided by later versions of curl.
This means CentOS5 curl does not include/support the flags "--tlsv1.1" or "--tlsv1.2".
RHEL7 and RHEL6 versions do support TLSv1.1 and TLSv1.2 and work when using them. One might need to run yum update for curl and/or openssl to have the versions with the support. On my RHEL6 systems I had...
