Build a Proxy-Auto-Config file

by: oswaldofarithPosted on 2009-05-19 at 17:43:17ID: 24427810

My recommendation is: Forget auto-config file. Use a free utility like

http://www.proxychanger.com/proxy-changer-download.asp
http://www.allscoop.com/dotnet-software/proxy-changer.php

or try a toolbar, extension, complement or whatever for your browser

http://ie7pro.com (for IE)
https://addons.mozilla.org/en-US/firefox/addon/1557 (for Firefox)

by: rustyrpagePosted on 2009-05-19 at 18:01:39ID: 24427880

How does that work in a company environment where we have no admins & block changes to Proxy. When in the office I do not want people to be able to bypass the proxy. When out of the office, I want it to go direct.

Make sense?

by: oswaldofarithPosted on 2009-05-19 at 21:37:46ID: 24428654

Ok, in that case you definitely need a pac file. Try this solutions:

http://www.experts-exchange.com/OS/Microsoft_Operating_Systems/Server/2003_Server/Q_23829236.html?sfQueryTermInfo=1+10+offic+proxi

http://www.experts-exchange.com/OS/Microsoft_Operating_Systems/Windows/XP/Q_21867608.html?sfQueryTermInfo=1+10+offic+proxi

by: rustyrpagePosted on 2009-05-20 at 07:25:06ID: 24432178

What if I ONLY want the proxy to proxy port 80 traffic? (not 443, FTP etc)

by: vkoyustuPosted on 2009-05-20 at 14:03:57ID: 24436289

You can user PAC or WPAD.

WPAD is very simple.
http://en.wikipedia.org/wiki/Web_Proxy_Autodiscovery_Protocol
http://www.findproxyforurl.com/

http://www.findproxyforurl.com/wpad_tutorial.html

WPAD Deployment Tutorial

PAC File Configuration

The WPAD specification demands that the PAC file be renamed to: wpad.dat
This is the only change required of a normal PAC file.
Web Server Configuration

IIS Server
1. Login to the server through Terminal Services or Remote Desktop Connection.
2. Click Start, select Programs, and then click Administrative Tools.
For IIS 5.0: Open Internet Services Manager.
For IIS 6.0: Open Internet Information Services.
3. In the left column you will see the Server Name.
In IIS 5.0: expand the Server Name to find the domain name.
In IIS 6.0: expand the Server Name and then Web Sites to find the domain name.
4. Right-click on the domain name and select Properties.
5. On the HTTP Headers tab click MIME Types.
6. Click New.
7. Enter the below information:
Extension: .dat
MIME type: application/x-ns-proxy-autoconfig
8. Click OK.

Apache Server
1. Create .htaccess file.
2. Add the below line into the file:
AddType application/x-ns-proxy-autoconfig .dat
3. Upload file to same location as wpad.dat file.
DHCP Server Configuration

We must configure the DHCP server to include a 252 entry in the DHCP information sent to a user. When configured this entry includes a direct link to the wpad.dat file.

Windows 2003 DHCP:
1. Click Start > Programs > Administrative Tools and then click DHCP.
2. In the console tree, right-click on the DHCP server, click Set Predefined Options, and then click Add.
3. In Name type: WPAD.
4. In Code type: 252.
5. In Data type select String, and then click OK.
6. In String, type URL of PAC file in format: http://url:port/wpad.dat
7. Right-click Server options and click Configure Options.
8. Confirm that the Option 252 option is selected.

Once created we must then enable the option for a DHCP scope.
1. Click Start > Programs > Administrative Tools and then click DHCP.
Right-click Scope Options and then click Configure Options.
2. Click Advanced, and then in Vendor Class, click Standard Options.
3. In Available Options, select the 252 Proxy Autodiscovery option and click OK.

Linux DHCP:
1. Edit the DHCP configuration file (usually /etc/dhcp/dhcpd.conf).
2. Edit and paste the following into the file:
option local-pac-server code 252 = text;
option local-pac-server "http://wpad.example.com:80/wpad.dat";
The first declaration must go in the global section of the configuration file.
3. Restart the DHCP server.
DNS Server Configuration

Windows 2003 DNS:
1. Click Start, click Programs, click Administrative Tools, and then click DNS.
2. In the console tree right-click on the applicable forward lookup zone and click New Host (A).
3. In Name type: wpad
4. In IP Address enter the IP address of the web server hosting the wpad.dat file.

by: rustyrpagePosted on 2009-05-20 at 15:13:22ID: 24436801

But I still don't see how to just set the HTTP traffic & not the others.

by: vkoyustuPosted on 2009-05-20 at 15:25:36ID: 24436882

What do you use as proxy server?
ISA Server or other solution?
You can configure a rule for HTTP on ISA server.
http://www.elmajdal.net/ISAServer/Allow_Internet_From_ISA_Server_Machine.aspx

by: rustyrpagePosted on 2009-05-20 at 15:29:06ID: 24436899

We don't use ISA - we are using an external service that does our filtering, so it is just a squid proxy.

by: vkoyustuPosted on 2009-05-21 at 05:08:01ID: 24440382

ok no problem
you can use any proxy with WPAD.
your clients are windows or linux?
did you test wpad anyway?

by: rustyrpagePosted on 2009-05-21 at 08:15:42ID: 24442395

My only problem with WPAD is that gets pushed to all users - I would prefer push a proxy auto-config setting via GPO to only select users. The fear I have is that our subnet is 10.1.x.x 255.255.0.0, so that could be common enough that it would cause problems at people's houses etc. Thoughts?

by: vkoyustuPosted on 2009-05-21 at 08:41:21ID: 24442704

Ok I understand,

What is your antivirus system? if you use Symantec endpoint protection and host integrity enable on SEP manager, you can set proxy config automatically only select users. you can config Office and outoffice group. So your users use proxy if they are in office with office policyi, then if they are their home you cannot use proxy with outofoffice policy:)

by: rustyrpagePosted on 2009-05-21 at 09:19:47ID: 24443156

Nope - we're still stuck on SAV 10.2

I can't be the only person with this issue, that's what's so surprising =)

by: vkoyustuPosted on 2009-05-21 at 11:00:51ID: 24444148

if you have SEP upgrade license immediately upgrade to sep 11 mr4
then I can help you:)

by: rustyrpagePosted on 2009-05-21 at 11:28:55ID: 24444437

I am really looking for something like the below code, but have it ONLY do HTTP traffic. I also need to know what some of the variables mean. I have no problem distributing it via GPO.

//modified 07/31/08 11:32 ch 
 
function FindProxyForURL(url, host)
{
 
 
var myip=myIpAddress();
 
 
 
//exceptions to proxy, traffic to local hosts is direct,
//also sites that have trouble with squid is direct
if (shExpMatch(url, "*mydomain.com*") ||
   shExpMatch(url, "*myotherdomain.com*")  ||
   isInNet(host, "172.19.0.0", "255.255.0.0") ||
   isInNet(host, "10.0.0.0", "255.0.0.0") ||
   isInNet(host, "127.0.0.1", "255.255.255.255"))
   		{
		//alert("direct") 
		return "DIRECT";
		}
 
else if (myip.substring(0,3)!=="10." && myip.substring(0,7)!=="172.19.")
		{
		//alert("direct")
		return "DIRECT";
		}
 
//use proxy unless unreachable, go direct if proxy is unreachable
 
else
{
//alert("proxy")
//return "DIRECT";
return "PROXY squid:3128; PROXY squidbak:3128; DIRECT";
 
}
 
}

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