RE: HTTP request working via hostname but not via IP address

[Marvin Simkin <Marvin.Simkin () asu edu>]

> The IP i'm trying to reach IS one of two IPs which correspond to a virtual adress, but this is on an internal 
> network, so the IP I am aiming for is definitely not virtual. Any other possibilities?

There may be some overlapping terminology here: "virtual IP" vs. "virtual host".

Try this:

telnet HOSTNAME 80
Trying ADDRESS...
Connected to HOSTNAME (ADDRESS).
Escape character is '^]'.
GET / HTTP/1.0


Then press return a second time. Note what you get for a reply. Then do this:

telnet HOSTNAME 80
Trying ADDRESS...
Connected to HOSTNAME (ADDRESS).
Escape character is '^]'.
GET / HTTP/1.1
Host: HOSTNAME


And press return again. If the responses differ significantly, the web server is configured to require the "Host:" 
header from your browser, which was included in the second request but not the first. When you connect by IP address, 
your computer maybe sends "Host: ADDRESS" or maybe no host header at all. Thus the server rejects the request.

Marvin Simkin, CISA
http://simkin.asu.edu/






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