The encryption using TLSv1 has been removed from 7.1.11, going forward. This removes the possibility of older sensors connecting to a CMC running 7.1.11.
Upgrade all sensors to 7.1.11 before connecting them to a Central Manager running 7.1.11.
SSLProtocol -all +TLSv1.2 +TLSv1.1
To add TLSv1, change the above line to the following:
SSLProtocol -all +TLSv1.2 +TLSv1.1 +TLSv1
Then save the file and restart httpd with: service httpd restart