Loopback DNS Entries in Hosts File Not Supported

Issue #8085332 • Assigned to Bruce M.


Lindsey T.
Jul 5, 2016
This issue is public.
Found in
  • Microsoft Edge
Found in build #
Reported by 6 people

Sign in to watch or report this issue.

Steps to reproduce

  1. Open C:\Windows\System32\drivers\etc\hosts in text editor in administrative mode.
  2. Add an entry for host name that is not “localhost” with loopback IP of, i.e.: mycomputer, then save the file.
  3. Open a command prompt in administrative mode and execute ipconfig /flushdns to clear the DNS resolver cache.
  4. In IIS or another web server on the same machine, configure site bindings for a site to respond to the host name that was chosen. For instance, in IIS:
  • Right click the site you wish to use, such as “Default Web Site,” and choose Edit Bindings.
  • Click the Add button in the Site Bindings dialog.
  • Type the host name, i.e. mycomputer, in the Host name field of the Add Site Binding dialog, then click OK.
  1. Open Edge and type the protocol and host name into the address bar, i.e. http://mycomputer, and press enter. The browser should fail to resolve the DNS entry correctly.


0 attachments

    Comments and activity

    • Microsoft Edge Team

      Changed Assigned To to “Brad E.”

    • I seem to actually be getting completely different results. The domain will not load for me in Edge - but does in Chrome.

      Curious - do you have localhost loopback enabled in the about:flags section of the browser by chance?

    • Brad E.:

      Localhost loopback is enabled. And resolving the localhost name works fine. But any other non-localhost entries that loopback fail to resolve (as you describe). Our methodology is to utilize a subdomain with *.local.mycompanydev.com to set up local instances on our machines for testing and development of our applications, but this is unworkable in Edge as they will not resolve (possibly due to logic surrounding that configuration flag).

    • Microsoft Edge Team

      Changed Assigned To to “Venkat K.”

      Changed Assigned To from “Venkat K.” to “Erik A.”

      Changed Assigned To to “Bruce M.”

    • I’m having the same problem, but I’m not even using a loopback address. I have a VirtualBox isntance running on my Windows 10 host, and host my development sites on that. I have entries in the hosts file for fully-qualified domain names (using our companies .com domain) pointing to a 10.0.x.x IP, which the Virtual Box host-only adapter. Works in every other browser but apparently not edge.

      And yes, I have Allow local loopback checked.

      Since neither a hosed virtual machine nor, from the OP, a local binding seem to work I can only conclude that Edge is broken for any serious web development. Something of an epic fail for a web browser…

    • I cannot repro on a newer preview build (14943). However, seeing another report via Twitter

    • I’m actually no longer experiencing this issue after upgrading to the anniversary edition build.

      Microsoft Edge 38.14393.0.0
      Microsoft EdgeHTML 14.14393

    • I am on Microsoft Edge 38.14393.0.0 and still have the issue

    • I actually just switched OFF the flag “Allow local host loopback” and it started working defying all logic.

    • I have this issue with Microsoft Edge 38.14393.0.0
      Same scenario as OP (local websites hosted in IIS 7.0 with Bindings set and hosts file entries that map to accordingly)

      Toggling ON/OFF the “Allow localhost loopback” in about:flags and then doing a full reboot has no effect.

      Chrome/IE11 - no issues

      Currently blocked from using Edge as a viable web browser for development.

    • Same here:
      Blocked from using Edge as a viable web browser for development.

    You need to sign in to your Microsoft account to add a comment.

    Sign in