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cwkim_261931's avatar
cwkim_261931
Icon for Nimbostratus rankNimbostratus
Jul 31, 2018

HTTP monitor send string about "host"

Hi   I use the HTTP monitor like this... GET /A/B/C.html HTTP/1.1\r\nHost: \r\nConnection: close\r\n\r\n   Almost server's state is UP   But someone is DOWN...   And I modify the send st...
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Filip_Mikulík_1's avatar
Filip_Mikulík_1
Icon for Cirrus rankCirrus
Jul 31, 2018

In HTTP v 1.1 is Host header mandatory. It is used for resolution destination web server (like the virtual host on apache, or server behind a reverse proxy,...).

 

  • cwkim_261931's avatar
    cwkim_261931
    Icon for Nimbostratus rankNimbostratus
    Jul 31, 2018

    I found this article.

     

    Note: HTTP/1.1 requires the Host header to be present in the request but does not require the header to contain a value. If you do not have a specific host name on your server, a value of Host: suffices in most cases. A null value is valid unless the HTTP server requires them for virtual hosting.

     

    (https://support.f5.com/csp/article/K3224)

     

    So, I want to know the reason of different result by using HOST and NULL HOST.