www.mytatasky.com site is not opening from our network. 
When
I once remove and apply access list (in/out) from Core switch firewall
vlan interface its work but after few hours its agin stop working. 
Anyone can know about dis issue why it is happening?

Hi,

Try enable logging of this acl and see what is exactly happening in this access control lists (ACLs) and to have insight of traffic as it traverses the network or is dropped by network devices. Unfortunately, ACL logging can be CPU intensive and can negatively affect other functions of the network device.

http://www.cisco.com/web/about/security/intelligence/acl-logging.html

Hope to Help !!

Ganesh.H