Today, I set up a new wifi network at home. Almost everything worked as before, only my KT didn't connect properly with it.
After finding out that it actually did correctly connect to the wifi network but the KT framework somehow failed to recognize that, I suspected my custom firewall rules (see this thread
) to be the culprit.
A little tcpdump session later, it looks like that the KT tries to verify a new wifi connection by downloading a file from Amazon: http://spectrum.s3.amazonaws.com/kin.../wifistub.html
The dialog between KT and Amazon is completely normal browser/webserver stuff:
GET /kindle-wifi/wifistub.html HTTP/1.1
User-Agent: Mozilla /5.0 (Linux; like iPhone; U; en-US) AppleWebKit/528.5+ (KHTML, like Gecko, Safari/528.5+) Version/4.0
HTTP/1.1 200 OK
Date: Sun, 19 Aug 2012 12:11:20 GMT
Last-Modified: Thu, 14 Jan 2010 03:23:46 GMT
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<title>Kindle Reachability Probe Page</title>
<META http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<!--81ce4465-7167-4dcb-835b-dcc9e44c112a created with python 2.5 uuid.uuid4()-->
<body bgcolor="#ffffff" text="#000000">
As far as I can tell, this file is the same since 2010 (see last-modified header) and doesn't get dynamically generated. This suggests that other Kindles also do this? But I didn't find lots on the net about this, only some japanese pages. The KT doesn't seem to send any overly sensitive data, the http headers don't contain anything that looks specific to my Kindle Touch. I guess, Amazon only sees the IP address.
For testing this behavior, you can go to Menu -> Settings -> Wi-Fi Networks, select the wifi connection you want to test and select "Forget" in the following dialog. When setting up the network again the KT will download the file.