What is the best way to defend against network sniffing?

Related questions

1. What kind of car does the sniffer drive?
2. Can you decrypt SSL traffic?
3. How do I stop Wireshark from capturing data?
4. What is password sniffing?
5. Can SSH be sniffed?
6. What is Eltima Software?
7. Can Wireshark capture VPN traffic?
8. Is it illegal to use Wireshark?
9. What is Usbpcap Wireshark?
10. Will there be a season 3 of silver spoon?

Tags

1. #exposes
2. #prevent
3. #access
4. #surface
5. #since
6. #attack
7. #intruder
8. #crosses
9. #reading
10. #prevents
11. #protocols
12. #managed
13. #encryption
14. #unauthorized
15. #network
16. #somehow
17. #sniffing