Make sure dns inspection is not disabled. This should look something like the following.
inspect dns preset_dns_map
If this is disabled, the dns keyword does not work. Additionally, you need to make sure you flush the cache on any internal dns server and client. This will force the actual dns request to go through the ASA.
Thanks for your help. its working now
I need one more help . i posted one more issue.but no one have replied. may be you can help
See this.if you can help tell me please
Thanks & Regards