how would you protect against a rogue dhcp server?

Its been an issue Microsoft have ignored for years, and still not actually fixed.

Much as I dislike Wikipedia, this article sums up most of it

http://en.wikipedia.org/wiki/Web_Proxy_Autodiscovery_Protocol

Having a rogue DHCP server to man in the middle attack is still not even accepted by Microsoft security as an attack vector

I run Ubuntu on my laptop at home (XP on my gaming desktop), and I had a patch for the proxy exploit yesterday when I got home.

Good to see companies moving quickly to squash bugs. :)

Cheers,
John