Description of problem: Using underscores in servername will result in a 400 Bad Request Version-Release number of selected component (if applicable): 2.4.25-1.fc24 Steps to Reproduce: 1. add a virtual host with servername and serveralias like test_this.local 2. add to /etc/hosts 127.0.0.1 test_this.local 3. Restart httpd and check http://test_this.local Actual results: Will result in 400 Bad Request Expected results: A 200 response. Additional info: After installing fedora 24 and finding this problem the solution was dnf downgrade httpd --allowerasing Which downgraded httpd to version 2.4.18-2.fc24 that accepts underscores. PS: I'm using a ProxyPassMatch directive in my virtualhost in order to use php54-fpm from remi's repo, but still, the error i report was solved by downgrading httpd to the mentioned version. Also 2.4.25-1.fc24 will also work if no underscore is found in the name, like test.local
Underscores are not permitted in hostnames and are now rejected. RFC 3986 sec 3.2.2 - https://tools.ietf.org/html/rfc3986#section-3.2.2 -- A registered name intended for lookup in the DNS uses the syntax defined in Section 3.5 of [RFC1034] and Section 2.1 of [RFC1123]. Such a name consists of a sequence of domain labels separated by ".", each domain label starting and ending with an alphanumeric character and possibly also containing "-" characters. Using "HttpProtocolOptions unsafe" should allow the old behaviour. https://httpd.apache.org/docs/2.4/mod/core.html#httpprotocoloptions