WPAD Auto Proxy Discovery - broken on iOS 4.2.1 ?
It looks like Auto Proxy Discovery (WPAD - http://en.wikipedia.org/wiki/WebProxy_AutodiscoveryProtocol) is not working on my iPhone Version 4.2.1.
It is working just fine on my MacBook 10.6.5 and on various Windows computers, all connected to the same wireless LAN that the iPhone is connected to. I'm using WPAD via the a DNS CNAME, not via DHCP options.
I'm pretty confident that I have had this working in the past when my iPhone was using version 3 software.
Symptoms:
a) If I select HTTP proxy "Auto" and put in either "http://wpad/wpad.dat" or "http://wpad.my.domain.name/wpad.dat", it all works as expected.
b) If I select HTTP proxy "Auto" and leave the URL field blank, the wpad.dat file is not loaded. I know this because the server that hands out the "http://wpad/wpad.dat" does not record a "hit" on the wpad.dat file. I've power-cycled my iPhone and it makes no difference.
c) When I connect my macbook to the same wireless network, and leave the proxy setting at "auto proxy discovery" (i.e. the default), the wpad.dat file is discovered, downloaded, and used correctly.
Is this a known problem with iOS 4.2.1?
iPhone 3GS, iOS 4, WPAD