Hi, I did a firewall test at pcflank.com and it told me I had the port 23 and the 80 opened. Then I came up with the concern if that’s normal or maybe there’s something I should change in CIS in order to work properly
Do you use a router? If so, these tests are probing your router, and not the firewall in CIS.
Yes, but actually I made the same test with the pc connected directly to the modem and I got the same results. How do I know if it is the modem that is configured that way or if it is my computer??
Many broadband modems contain a router, so connecting directly to the modem may still have you sitting behind a router.
The easiest way to tell if you’re testing the router or your software firewall is to disable the firewall in CIS and run the tests again. If there is no change in the results, your router is being tested, not your software firewall.
I learn everyday ^^ it seems it actually test the modem, got same results. Thanks
Is there any specific way to actually test directly the firewall??
You would need to put your router into DMZ mode, which will allow all traffic to pass unhindered through your router to your PC.
You’ll need to refer to your router’s documentation for details on how to accomplish this. With some modem/router combos, it’s as easy as selecting a device name from a dropdown menu.
Edit: If you are in fact sitting behind two routers, you’ll need to enable DMZ on both devices.
It’s probably going to be a good idea to permanently DMZ your router through your modem/router. Otherwise you could experience a double NAT situation.
I understand, the only trouble I’m having is that my ISP won’t let me handle the modem’s configuration the only thing I can configure it’s the router. But, am I really protected?? it’s just that those results telling me I had open ports makes me a little uncomfortable so I actually not sure. I believe that Comodo’s firewall got’s my back but still that configuration it’s a little weird, so I would appreciate if you could clarify me those details 
Thanks
Since you are using a router the PC Flank website is actually probing your router. CIS still has your back.
Putting your computer in DMZ mode is an action done on the router which does not require any actions with your modem. Your computer is then directly facing the web when in DMZ. That’s the only way to make sure PC Flank is testing your computer’s firewall.
Thanks for the help I do trust Comodo ^^