Identify Client Cipher Strength

What type of information are you looking to get about the weak encryption clients?

You could either check the access logs for the URL you're redirecting them to, or you could log details in the rule itself:

http://devcentral.f5.com/wiki/default.aspx/iRules/RedirectOnWeakEncryption.html

 
 when HTTP_REQUEST { 
  
     check for at least 128 bits of encryption 
    if { [SSL::cipher bits] < 128 }{ 
  
        when browser cannot do at least 128 bits of encryption log client details 
       log local0. "Client IP:port: [IP::client_addr]:[TCP::client_port], Host/URI [HTTP::host][HTTP::uri],\ 
          User-Agent: [HTTP::header User-Agent], Auth header: [HTTP::header Authorization], cipher bits: [SSL::cipher bits]" 
  
        and redirect to a un-encrypted page with an informational error 
       HTTP::redirect "http://10.10.10.10/error/sslerr.html" 
    } 
 } 
 

Aaron