I have a SonicWall Pro 2040.
The VPN is configured to use L2TP with 3DES encryption.
Using Windows 7's built-in VPN support, I created a connection and it works fine.
However, I also have Mac users who need to connect remotely. Apparently Apple no longer supports 3DES in their latest OS (10.7 Lion). I was told the VPN software built into Lion only supports AES encryption.
So, I logged into my Pro 2040 and changed the encryption from 3DES to AES-256 and sure enough, it works! My Mac users can now connect.
Well ... now my Windows 7 users CANNOT connect!
The VPN settings on Windows 7 are pretty basic. There's no place to specify the encryption type to match the VPN Server. I probably tried every possible combination of settings but I cannot get it to connect to my Pro 2040.
If I set the VPN Server from AES-256 back to 3DES, my Windows 7 users can connect right away but as you can probably guess, now my Mac users CANNOT connect.
Note: I tried using AES-128 instead of 256 to see if that would work; it did not
I read somewhere online that Windows 7 supports AES (I would expect it to), but I cannot get it to work.
So it appears that:
- Windows 7 supports 3DES but not AES.
- Mac OS X 10.7 supports AES but not 3DES.
(One more thing I wanted to mention ... on the Mac side, there is a third party VPN software client called Equinux VPN Tracker. I tried it out and it works beautifully. In other words, I can set my VPN back to 3DES and that makes my PCs happy. And using Equinux (instead of the Mac's built-in VPN client), the Macs are happy) But that software is too expensive)