Package manager in Visual Studio 2015 “407 (Proxy Authentication Required)”

Question

I understand this is an often asked question, however after days of research I\'ve not found an answer to this particular problem.

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I have a new ASP.NE

Answer 1

I had the same problem a few weeks ago. For me it has helped to put in the the following in the machine.config (Windows/Microsoft.NET/Framework64/v4.0.30319/Config)

<system.net>
   <settings>
       <ipv6 enabled="True"/>
   </settings>
   <defaultProxy useDefaultCredentials="True" enabled="True">
       <proxy proxyaddress="http://your.proxyserver.ip:port"/>
   </defaultProxy>
</system.net>

Answer 2

You need to modify file 2 .config files:

for Visual Studio 2015

• C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\vsn.exe.config
• C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\devenv.exe.config

for Visual Studio 2017

• C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\vsn.exe.config
• C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\devenv.exe.config

<system.net>
  <defaultProxy enabled="true" useDefaultCredentials="true">
    <proxy usesystemdefault="True" bypassonlocal="True" proxyaddress="http://yourproxy:proxyport" />
    <bypasslist>
      <add address="(.*\.)?anyotherdomain\.com?(.*)" />
      <add address="(.*\.)?nuget\.org?(.*)" />
      <add address="192\.168\.\d{1,3}\.\d{1,3}" />
    </bypasslist>
  </defaultProxy>
  <settings>
    <ipv6 enabled="false"/>
    <servicePointManager expect100Continue="false"/>
  </settings>
</system.net>

The bypass for nuget.org will work if, without the proxy, you still can get it's IP from DNS server and nothing else is blocking it.

Also need this to install nuget

Open the file C:\Users\[YOUR_USER_NAME]\AppData\Roaming\NuGet\NuGet.Config and add inside the <configuration> <\configuration> tag the following:

<config>
  <add key="http_proxy" value="http://yourproxy:proxyport" />
</config>

Taken from Marco Mengoli's Blog