The beginner demanded to block icmp
As for you:
1) Create a complete plan of network interactions with hundreds of servers and thousands of clients on dozens of sites.
2) Strictly ensure that McAfee’s corporate antivirus exclusively stands on corporate computers. That catches exclusively "Uzbek viruses". (Be careful, this message contains a virus)

Striped by! I am a Uzbek virus. Because of the terrible wickedness of my creator and the low urvin development of technology our country I am not able to cause any device your computer. Patamu očna prašju Was, pažalsta, themselves satriite what-nibut important for Was file, and patom disperse the mail of another address, Saraniya Blagadarin for panimaniya and co-workers.