Description of problem:
Using underscores in servername will result in a 400 Bad Request
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. add a virtual host with servername and serveralias like test_this.local
2. add to /etc/hosts
Restart httpd and check http://test_this.local
Will result in 400 Bad Request
A 200 response.
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.