The request failed with HTTP status 503: DNS Fail

Question

I have a host named site collection and on the host file I have 127.0.0.1 pointing to that host name.

I created the search service application but when I try to crawl I get this error:

The crawler could not communicate with the server. Check that the server is available and that the firewall access is configured correctly. If the repository was temporarily unavailable, an incremental crawl will fix this error. ( Error from SharePoint site: HttpStatusCode ServiceUnavailable The request failed with HTTP status 503: DNS Fail.; SearchID = 79904609-8252-4DF4-B240-CB489C002CAD )

I checked IE settings on the server and there is no proxy setup.

Any idea how should I fix this crawling

Answer 1

First thing to check is if that web application has a root site collection. Check these sources: 1 (Technet) and 2 (wictorwilen.se).

Then, if sites are https-protected, I'd double check trusts if custom CA is used.