Visitor with no IP address, How Possible?

[jim_boston]

I logged the following visit the other day:

mystery-machine - - [25/Sep/2003:19:24:44 -0400] "GET /foo/foo/stylesheets/index.css HTTP/1.1" 304 - "http://www.foo.org/foo/foo/index.htm" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; Crazy Browser 1.0.5)"

Can anyone tell me how it is possible for someone to execute a GET without logging their IP address? I'd be very grateful.

[anchordesk]

Just a thought, but mystery-machine.com resolves to a valid IP address. Is your logging set to record hostname lookups instead of IP? Why it would record as just mystery-machine ... don't know.

[jim_boston]

Well, that explains that. Thank you very much.