404 header - HTTP 1.0 or 1.1?

Question

Why does almost every example I can find (including this question from about a year ago) say that a 404 header should be HTTP/1.0 404 Not Found when we\'ve real

Answer 1

It does not matter all that much. The client is responsible for telling the server which version of HTTP it uses. Then, the server is supposed to answer with the same version. This does not always happen; I just got this response from a server:

$ telnet example.com 80
Trying 123.123.123.123...
Connected to example.com.
Escape character is '^]'.
GET /fork HTTP/1.0

HTTP/1.1 404 Not Found
Content-Length: 1635
Content-Type: text/html
Server: Microsoft-IIS/6.0
X-Powered-By: ASP.NET
Date: Tue, 04 May 2010 22:30:36 GMT
Connection: close

I asked the server to use HTTP 1.0, but it went ahead and responded with HTTP 1.1.