Passing a header value to lb to pool

To decrypt/encrypt cookies... create values for your cookie name $ckname, and cookie password $ckpass in the client connected event.

when CLIENT_ACCEPTED {
      Name for the cookie to be inserted to maintain client session
     set ckname 
      Encryption password to be used for encrypting / decrypting the user session cookie
     set ckpass 
  }
when HTTP_REQUEST {
     if {[HTTP::cookie exists $ckname]} {
          Decrypt the cookie so we can use the values in it
          HTTP::cookie decrypt $ckname $ckpass 128
     }
}
when HTTP_RESPONSE {
        Set up your cookie details here
        Now to encrypt your cookie
 HTTP::cookie encrypt $ckname $ckpass 128 
}