Sharepoint search crawl failed

Problem:
Sharepoint's indexing service unable to crawl site. Error given as follows.
[To be updated]

Possible Solutions:
1) In my scenario, the problem was caused by a impersonate="false" setting in web.config. Somehow, the Indexing service requires impersonation to be true. However, some custom Sharepoint pages may require impersonation to be disabled. If impersonation cannot be enabled for your application, try the following alternative.

In Sharepoint's Central administration, you can extend the web application. By doing this, you are essentially creating a second web app site (with a different port number) for your application. However, the content source are shared with the original web app. Thus both sites are actually identical. Now, the newly created web app site would have impersonation enabled by default.

In your crawler settings, replace the original site path with the new port number.
Eg: Original is http://mysite, New is http://mysite:2434

The indexing/crawling will now function and search results will be redirected to http://mysite.

[Detailed steps to be updated]