Important aspect: note the existence of an
> HEAD http://ironbark.bendigo.latrobe.edu.au/
Etag:header. Note that
Ironbarkalso sends the
telnet proxy.latrobe.edu.au 8080. Once connected, the GET command is the same as usual except you request a full URL. Here's a transcript of me doing exactly this. Note that the first "
>" is my Unix prompt.
Try it. In fact, use it attempt to fetch some other external Web pages. Note that you may have to type the "Escape character" (control-right-square-bracket) and "c" to explicitly close the connection, since
> telnet proxy.latrobe.edu.au 8080 Trying 18.104.22.168... Connected to proxy.latrobe.edu.au. Escape character is '^]'. GET http://www.unimelb.edu.au/ HTTP/1.0 HTTP/1.0 200 OK Date: Tue, 25 Mar 2003 08:56:55 GMT Server: Apache/1.3.27 (Unix) mod_perl/1.27 mod_ssl/2.8.11 OpenSSL/0.9.6e Content-Type: text/html Age: 9403 X-Cache: HIT from squid2.latrobe.edu.au Proxy-Connection: close <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>Welcome to the University of Melbourne</title> ...etc... ^]c
proxy.latrobe.edu.auseems to occasionally default to
Connection: keep-alive-- although it didn't when I ran this particular example.
HEADutility to fetch pages via the La Trobe proxy server. This can be used to see which of the HTTP headers are sent. For example, try this:
Note any interesting headers. Can you see any that appear to relate to cache control, but weren't mentioned in the lecture? You should.
> HEAD -p http://proxy.latrobe.edu.au:8080 http://www.abc.net.au/news
Repeat the exercise with some other pages. For example, you might try
http://www.theage.com.au/ and some of more "famous" Web
site home pages.