How to get Windows 7 to shut up with the DHCPINFORM requests
-
My pfsense DHCP log was being flooded by DHCPINFORM requests from a Windows 7 machine as a result of WPAD, apparently. It keeps on doing it until you give it what it wants, once a minute or so.
Most of the threads about WPAD here are having to do with getting it to work, which is normal for the systems involved, but home users almost never need it, because we don't use proxies, and even if we did we could set it up manually (not sure how VPN might fit into this).
I first tried at the Windows 7 machine to get it to stop. However apparently just turning it off on the browsers, while they may no longer go out looking for proxies, the service in question still goes out and pesters the DHCP server (and DNS too I guess). Some say not to shut that Windows service down, so I left it alone. The DNS accesses from WPAD are actually a security hole.
So, in pfsense I just went to the DHCP service, and opened the Additional BOOTP/DHCP options, and entered '252' in the number field, 'string' in the type field and ' "\n" ' in the value field (include the double quotes but not the single quotes). I then looked in the DHCP log again; the Win 7 machine did one more DHCPINFORM and then was satisfied.