Dear,
I wanna to block .com/.net etc. If any idea then please help me.

Thanks/vendam

Hi,
are you want to block all .com & .net domain?

Only by firewall?
Seems to me it's better to do it by web proxy access.

as artsmolkin writes - use the transparent proxy configuration with rules set to what is allowed/denied with proxy caching disabled. That will consume less resources that doing same via firewall.

as artsmolkin writes - use the transparent proxy configuration with rules set to what is allowed/denied with proxy caching disabled. That will consume less resources that doing same via firewall.

Yes Proxy Caching is high CPU consumer!!! if you are using low end router better not to use proxy caching.