Error 1013 HTTP hostname and TLS SNI hostname mismatch

The description on this error page reads:

You've requested an IP address that is part of the Cloudflare network. The request's Host header does not match the request's TLS SNI Host header

Most modern HTTPS clients send a Server Name Indication as part of the TLS handshake, when this name does not match the HTTP request's host header, a Cloudflare Error 1013 is presented.

The most common reason for seeing this message is if your local machine or network is proxying SSL traffic. Some SSL proxies have implementations that can cause an inconsistency between the SNI and the Host Header.

One useful way you can test whether your machine or connection is sending mismatched information is to visit an online tool such as:

https://cc.dcsec.uni-hannover.de/

This will provide a report of the SNI that was sent, if everything is working correctly the "SNI information" section should read:

SNI information: cc.dcsec.uni-hannover.de
 
If you see something else listed, then that is a good indication that your browser is not able to make a proper request over TLS for sites on our network. You should contact your local network administrator or ISP for guidance on what specifically is causing this.
 
If you're unsure, you can write to Cloudflare Support and provide the following information:
  1. A HAR file capturing the request where you see the error - How do I generate a HAR file?
  2. A screenshot of the output from https://cc.dcsec.uni-hannover.de/

So we can take a look and guide you further.

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