DoD CAC Auth with LTM

If you want to authenticate the user's client certificate on the BIG-IP then you use the Client SSL profile as you have done. When they connect they will be presented with a dialog box asking for a cert, if it is incorrect they will get an SSL error. This can also be done with APM which gives a nicer user experience ie it can tell them what went wrong, or you can do that with iRules.

However, if you then want to present that client certificate to the web server then you need to work out how to do that. Essentially there are two ways - add the client cert in an HTTP header (using an iRule or policy), or present it at the SSL layer using Client Certificate Constrained Delegation (C3D) https://my.f5.com/manage/s/article/K14065425