Prevent packet sniffing with DD-WRT, PPTP and VPN

If you connect to the internet wirelessly, a firewall and antivirus software won’t prevent possibly sensitive information — transmitted from your laptop to the router — from being seen by packet sniffers. Why do you need to implement a security system like this? (My emphasis added.)

Uses of packet sniffers: “Spy on other network users and collect sensitive information such as passwords (depending on any content encryption methods which may be in use)”

The bits that fly through the air are probably unencrypted by default. In a setting where the wireless access point is wide open, your data can be transmitted in plain text.

When I bought my Linksys WRT54GL and installed DD-WRT last July, I didn’t realize I didn’t need to use Hamachi and Remote Desktop to prevent packet sniffing.

Five months before I bought my new router, Scott Hanselman wrote, “Configuring PPTP VPN with alternate Linksys Router Firmware.” Here’s some additions I’d like to offer:

• My server IP is the same as my router.
• Dynamic DNS through DynDNS is free!
• In DD-WRT v23 SP1, you can find the PPTP Server settings under Administration > Services.
• Generate a password from GRC, and see Microsoft’s Password Checker.
• I manually selected MS-CHAP v2. It seems secure enough to encrypt all my packets.

Today, I’m at the Arcadia Public Library working on an essay and studying for finals, in addition to testing PPTP VPN for the first time ever. Trying to scare my mom, I printed to my home printer. I browsed my home computer’s shared folders. Lastly, I was sniffing packets with Sniphere. Filtering my assigned IP address at the library, all of the packets showed a bunch of gibberish. Yes!

Unlike the Hamachi solution, there shouldn’t be any downtime because my router is always on. Also, I don’t need to keep my computer on, unless I need file access. I think this means I don’t need Hamachi anymore.

Besides buying the DD-WRT-supported router, which I needed anyway, this setup was free!