I noticed you said that you checked your proxy settings...3 tips that worked for me.
1. Google Chrome and Internet Explorer both did not connect well for me. Firefox did (not promoting Firefox this is one of the few things I use it for)

2. Disable the proxy setting in your browser and try connecting to ntop. If that works dig into your bypass list.

3. Make sure if you have a manually configured proxy setting in your browser that you add the local ntop IP address to your proxy bypass list (just the IP...do not put the http or the :3000 in the bypass)

Hello, I"m having similar problems. ntop installed ok, and the service is running.
netstat -ntlp | grep ntop
tcp 0 0 127.0.0.1:3000 0.0.0.0:* LISTEN 18899/ntop
tcp 0 0 127.0.0.1:3001 0.0.0.0:* LISTEN 18899/ntop

I am connecting from the LAN side, but nothing comes up when I browse to port 3000 (or https on 3001, for giggles) on the firewall. (ClearOS 6.5x64) Similarly, I can't telnet to port 3000.

Ntop 5.0.5el16 was the version that installed. The conf file lists:
# limit ntop to listening on a specific interface and port
--http-server 127.0.0.1:3000 --https-server 127.0.0.1:3001

Do I need to change those to the LAN IP?

What should I check next?
Thanks!

As Tim said check if there you have port 3000 listening.
Also check the definition in /etc/ntop/.conf file and the binding interface/ip
Try restarting the service and reconfigure : ntop -A

g.l

Hi Kenneth, whats the output of 'netstat -ntlp | grep ntop'?

If you are connecting from the LAN you shouldn't need to open up any firewall ports