after running
dotnet new react
dotnet restore

gives the following issue

C:\Program Files\dotnet\sdk\2.0.0-preview2-006497\NuGet.targets(102,5): error : Failed to retrieve information about 'Microsoft.VisualStudio.Web.CodeGeneration.Tools' from remote source 'http://nuget.dev-web-01.csdev.com.au
/nuget/FindPackagesById()?id='Microsoft.VisualStudio.Web.CodeGeneration.Tools''.\r [C:\Training\TrainingSample.csproj]
C:\Program Files\dotnet\sdk\2.0.0-preview2-006497\NuGet.targets(102,5): error : Response status code does not indicate success: 404 (Not Found). [C:\Training\TrainingSample.csproj]