how block whatsapp in my network ??

Not sure exactly what you mean. What type of network are you talking about? Whatsapp runs on smartphones. Is there a client app that runs on PCs?

It is probably very hard to do it on firewall level, since most firewalls (kerio too) are Layer 3 firewalls, so you would need to know all the IP addresses, which are in use with Whatsapp messenger. Which is utopia.

I suggest you "dirty" approach.
You might use Group Policy to push a firewall rule to client computers, which prevent c:\Program files\Whatsapp\whatever.exe from communicating with internet.

Also you might create a simple BATCH file, which runs from server, and scans all available IP's on your LAN, look for c:\Program files\whatsapp\whatever and try to delete whatsapp.exe or however it is called.

Or even more  - with above script you might just scan for Whatsapp installed in Program Files, and if found, push the new IP address to the client and move him/her into some weird IP subnet, for example, to 10.10.100.xxx range. Client will loose internet AND LAN connectivity and will call you for help. You will slowly respond, then you will examine his/her computer and diagnose, that he/she had WhatsApp installed, and that's why computer was "broken".
Few interventions like this and all will know that there is no kidding at work. :)

***EDIT***
Sorry, if this is for smartphone, my suggestions do NOT apply.

there is no whatsapp application in the windows , I want to disable whatsapp in all smartphones in my Network ,because it is waste of time in work time .

I block connection to port :5222 ,5223 , 5228 from my firewall
and I create a rule to block access to whatsapp.com and whatsapp.net but whatsapp application continue to work .

any idea ??

From what I've read, whatsapp will use port 80 or 443 to try and bypass firewall restrictions. You would need an application layer firewall that is actually scrutinizing the contents of packets to block it.

Even then, any rules you make would only work when the smartphone is actually on your wifi network. Any phone using the 3G network is outside of your control and you can't block them.

So really there isn't anything you can do at a technical level. Instead, you should enforce a "no playing on cell phones" company policy.

sure I want to block whatsapp for the smartphone using our wifi network not for 3G sure.
so what IP should I block in my firewall ???

yes Kerio control has application-layer blocking and protocol inspection ..

I try block all chat application but no luck .
how can I use the protocol inspection to block whatsapp ??

ok now I did it.
I successfully block whatsapp in my network .
I know now what ip and port is using by whatsapp and I block them.
trying many times from the firewall log and I did it.

thanks for all

I've requested that this question be closed as follows:

Accepted answer: 0 points for spring80's comment #a38753781
Assisted answer: 500 points for Frosty555's comment #a38749396

for the following reason:

thanks

thanks