Hi,
You don't use a client ssl for admin access. you have to use tmsh in order to disable ciphers on admin access.
First of if you want to check cipher used, enter this command:
list sys httpd ssl-ciphersuite
sys httpd {
ssl-ciphersuite ECDHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-RSA-AES256-SHA:ECDHE-RSA-AES128-SHA256:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA:ECDHE-ECDSA-AES128-SHA256:ECDHE-ECDSA-AES256-SHA384:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA:AES256-SHA:AES128-SHA256:AES256-SHA256:ECDHE-RSA-DES-CBC3-SHA:ECDHE-ECDSA-DES-CBC3-SHA:DES-CBC3-SHA
}
So if you want to disable 3DES you can just add
:!DES:!DES
at the end of the line.
So to modify SSL-Ciphersuite follow this procedure:
tmsh modify sys httpd ssl-ciphersuite 'ECDHE-RSA-AES128-GCM-SHA256:....:!DES:!DES'
tmsh save sys config
bigstart restart httpd
Keep me in touch.
regards