[londons_explore]

Google's model requires two factor user auth, and trusted hardware.

Even someone with serious hardware-foo would only be able to maybe break the trusted hardware bit (by cloning one device id to another, or emulating a device). They couldn't get round the two factor authentication bit.

I'd say it's still a pretty watertight model.

[pizzetta]

Like many things, I'm sure you can make a case for exceptions or whitelists --although granted they likely monitor and or shunt traffic to less trusted vlans or something?

[londons_explore]

The ultimate BeyondCorp setup has no vlans. All networking kit is considered untrusted (and can be the public internet). All traffic is end to end encrypted between the employees device and the specific server they want to communicate with via HTTPS.

Obviously, getting entirely to that model is a lot of work, mostly for services which don't use HTTPS (network shares, ftp, smtp, ssh, enterprise java apps, etc.)