Nimbostratus
Nimbostratus
Yes. The F5 can detect if the Client has a Client SSL Certificate. This is configured in the Client side SSL Profile (what is applied in the Virtual Server under SSL Profile (Client)).
To configure the profile you go to (on v10.x.x): Profiles -> SSL -> Client
Select the Client SSL Profile (or create a custom SSL Profile (Recommended)) and scroll down to the "Client Authentication" Area. The help for these options are pretty good so you should not have any problems configuring the base requirements.
You will then need to decide what to do with what you get. That is all pretty much handled by an iRule. I would suggest reading up on the iRule event that you will be needing (CLIENTSSL_CLIENTCERT): http://devcentral.f5.com/wiki/iRules.CLIENTSSL_CLIENTCERT.ashx
Here is a really good example. This iRule requests a Client SSL Certificate based on the URI:
http://devcentral.f5.com/wiki/iRules.client_cert_request_by_uri_with_ocsp_checking.ashx