Cisco Systems RVS4000RF manual MAC Address Spoofing, Data Sniffing, Man in the middle attacks

Planning Your Virtual Private Network (VPN)	3
Why do I need a VPN?

1) MAC Address Spoofing

Packets transmitted over a network, either your local network or the Internet, are preceded by a packet header. These packet headers contain both the source and destination information for that packet to transmit efficiently. A hacker can use this information to spoof (or fake) a MAC address allowed on the network. With this spoofed MAC address, the hacker can also intercept information meant for another user.

2) Data Sniffing

Hackers use data “sniffing” to obtain network data as it travels through unsecured networks, such as the Internet. Tools for just this kind of activity, such as protocol analyzers and network diagnostic tools, are often built into operating systems and allow the data to be viewed in clear text.

3) Man in the middle attacks

Once the hacker has either sniffed or spoofed enough information, he can now perform a “man in the middle” attack. Hackers use this attack when data is transmitted from one network to another, by rerouting the data to a new destination. Even though the data never reaches its intended recipient, it appears successful to the person who sent the data.

These are only a few of the methods hackers use, and they are always developing more. Without the security of your VPN, your data is constantly open to such attacks as it travels over the Internet. Data travelling over the Internet often passes through many different servers around the world before reaching its final destination. That’s a long way to go for unsecured data and this is when a VPN serves its purpose.

Cisco RVS4000 Security Router with VPN Administrator Guide 14