try "curl http://##.##.##.##:100" and see what that gets you. it may display more useful information than your web browser.
there could be a proxy server issue in the mix, locally or at your isp?
"curl http://##.###.###.###:100/home.cgi" returns:
Artie-s-Computer-4:~ artie$ curl http://##.###.###.###:100/home.cgi
curl: (52) Empty reply from server
Artie-s-Computer-4:~ artie$
(Note that, as explained in my post to tacit, that is the correct target URL.)
Does that mean anything to you?
Thanks.