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Unformatted text preview: le /index.html. It also informs the server that the remainder of the request will be in HTTP/1.1 format. Request headers provide additional information to the server, such as the brand name of the browser or the MIME types that the browser understands. Request headers have the form
<header name>: <header data> For our purposes, the only header we need to be concerned with is the Host header (line 5), which is required in HTTP/1.1 requests, but not in HTTP/1.0 requests. The Host header is only used by proxy caches, which sometimes serve as intermediaries between a browser and the origin server that manages the requested ﬁle. Multiple proxies can exist between a client and an origin server in a so-called proxy chain. The data in the Host header, which identiﬁes the domain name of the origin server, allows a proxy in the middle of a proxy chain to determine if it might have a locally cached copy of the requested content. Continuing with our example in Figure 12.41, the empty text line in line 6 (generated by hitting enter on our keyboard) terminates the headers and instructs the server to send the requested HTML ﬁl...
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- Spring '10
- The American