I installed Google’s Secure Access VPN client and I’ve made some observations.

I’m not sure if the setup program created it or if the the client
itself created it but there is a new network connection in the Network
Connections control panel. This seems to be your standard PPTP VPN
connector.

Opening the connector is see that the username is listed as 0633492659
(seems to be a randomly generated number by the client as the second
time I connected I was assigned this number: 2466407433)
and there is no password saved. I’m assuming that the Secure Access
Client fills in the password, but that’s just an assumption.

Looking at the properties, I see that the connector is connecting to
vpn.google.com, and there are several advanced security settings
specified. According to the connector, the server requires encryption
(disconnects if the server declines) and the following options are
checked under Allow these protocols:

• Challenge Handshake Authentication Protocol (CHAP)


• Microsoft CHAP (MS-CHAP)


• Microsoft CHAP Version 2 (MS-CHAP v2)

All of the other options are unchecked.

Once I opt to connect the Secure Access Client, it starts the VPN
connector and automatically connects me. The following information is
listed in the Details section of the VPN connector:

• Authentication: MS CHAP V2


• Encryption: MPPE 128


• Compression: (none)


• PPP multilink framing: Off


• Server IP address: 192.168.230.1


• Client IP address: 192.231.7
  

Doing a quick Ethereal packet capture from my laptop, it looks like the
Secure Client makes some SSL calls to vpn.google.com before connecting the VPN network connection; it probably does
this to get the username and the password to connect to the VPN.