F5 iRule – User Agent

when HTTP_REQUEST {
set HOST [string tolower [HTTP::host]]

if { ($HOST eq "domain.com" || $HOST eq "www.domain.com" ) and 
         ([HTTP::header User-Agent] contains "Chrome/33.0.175") and
            ([HTTP::header User-Agent] contains "(X11; Linux x86_64)") } {
                reject
               }
}

The above iRule will enable the F5 to send a TCP RST (reset) to the client for a specific domain and specific User-Agent information within the incoming HTTP Request.