69
36
When Internet Explorer is set to auto-detect proxy settings, is there a way to view what it detects?
69
36
When Internet Explorer is set to auto-detect proxy settings, is there a way to view what it detects?
52
The settings are retrieved from http://wpad/wpad.dat which is a javascript file describing which proxy server should be used in which situation. Your best bet is to open that URL and figure the proxy out from the contents it returns.
46
If http://wpad/wpad.dat
is not available, you can deduce which proxies are in use by browsing to a web site and then checking the TCP connection that was made. It's not great, but it's at least minimally useful.
netstat -an | find "EST"
(short for 'ESTABLISHED
').Run the netstat
command again, looking for the new connection. It might look like:
TCP 192.168.1.1:1989 192.168.1.88:8080 ESTABLISHED
In this example, your proxy's IP is 192.168.1.88
and it is listening on port 8080
.
Note that this method only shows the proxy currently in use for that connection. If more than one proxy is configured in your environment, and you want to know all of them, you may need to repeat the procedure above periodically to get the full list.
The same procedure can be used on non-Windows boxes (using netstat -an | grep EST
, or whatever your OS uses to show active connections).
Great indeed... – majkinetor – 2015-12-16T22:30:11.347
Nice workaround :) – hoang – 2013-06-10T13:23:59.840
18
I tried both solutions mentioned, and also all sorts of others.
In the end what worked for me was using Chrome to navigate to:
chrome://net-internals/#proxy
which gave me the .pac
file (= proxy auto-config file) which I could then download and read to determine the proxy that was being selected.
=== Addenda ===
As pointed out by @DaveInCaz and @ZachBloomquist, this no longer works as of Chrome 71.
So what I did was:
chrome-win32.zip
.chrome.exe
and you can again use the address chrome://net-internals/#proxy
to find the PAC script!So to summarize the steps required:
chrome.exe
chrome://net-internals/#proxy
2Apparently this no longer works? Chrome does not display any useful information on that page. version 75 – UuDdLrLrSs – 2019-07-17T17:05:18.337
1@DaveInCaz thanks, I've added a workaround! – SharpC – 2019-07-22T10:51:05.857
good idea, thanks. – UuDdLrLrSs – 2019-07-22T11:40:54.983
As mentioned elsewhere, the actual proxy can be found in lines with
– Tobias Kienzler – 2015-11-06T08:19:05.087PROXY
- in my case I had to track back an array's generation function, though...1
Ah, excellent. Here is more detail on the Web Proxy AutoDiscovery protocol: http://en.wikipedia.org/wiki/Web_Proxy_Autodiscovery_Protocol
– Aidan Ryan – 2009-09-01T23:22:11.990Are you sure that's the link? What's wpad's top level domain? – Nathan Fellman – 2009-10-10T08:38:53.743
Oh... I see. I should use wpad in my local domain – Nathan Fellman – 2009-10-11T06:20:14.117
1This doesn't work for all networks. Sometimes proxy is autodetected over dhcp (inform verb) rather than http wpad. – Colonel Panic – 2013-07-01T12:58:25.093