Firewall Oddness


Just recently installed Internet Security (v3.12.111745) and it had been running well for a couple of weeks. Starting this past weekend (I am assuming after an update) the f/w seems to have begun blocking a number of sites that it had allowed in the past and that I don’t want blocked. I have selected a different configuration and that seems to help (not 100%), but I would like to use the most recent version of the engine/files. I was unable to find a way to whitelist a URL, so I am hoping someone can point me in the right direction as to what I may have done wrong/how to whitelist. By way of example the following sites are blocked when I use the “Comodo - Internet Security - Updated” config, but not using the “Comodo - Internet Security” config:

Thoughts or suggestions are appreciated. Not sure what info is required to assist, so if I have neglected a key piece of info please let me know.


By chance do you use Comodo DNS servers?

No I don’t. Currently, I am configuered to obtain my DNS automatically.


comodo does not block url’s you visit unless you are using their domain name servers. it will however block a website if you have its ip blocked. so say for instance you blocked an ip range like -
any websites that happen to have an ip in that range would be blocked. a domain name servers takes a name ( and turns it into an ip ( this makes it much easier for you. try using comodo’s dns servers or and see if this resolves your issues. (by default you will obtain your dns from your isp, my isp was unreliable sometimes so i switched to opendns and this helped me)

Not to ask a dumb question, but if I am using their dns servers that would be reflected in my network properties (i.e. their dns ip addresses listed) right? If that is the case I am definetely not using their dns servers. The thing that is odd is once I change the configutation or turn off the f/w things work like a charm. I will try and purge my list of blocked urls (not that many) on the off chance I introduced a problem there.

Thanks for the info on trying their dns or opendns I will give that a try as well.

yes it would reflect there and it would also show when u visited a domain name that didnt exist.

you can alternatively set the dns in your router as well and it would not reflect on your computer, but this would definitely be something you remembered doing and is by default set to obtain dns from your isp.

Can you post links to some websites that are blocked.

Also did you change internet companies recently? Your ISP maybe blocking them for you.

But i think i know what you mean.

Thanks for the suggestions, but no I haven’t changed ISPs. I was trying to view the following:

Since disabling the f/w resolves the behavior and it seemed to occur following a CIS update I decided to uninstall and reinstall the orginal verions I d/l (3.11.108364.552). If the behavior reoccurs I will be back :slight_smile:


Can you see if there are any blocked sites under Firewall → Common Tasks → My Blocked Network Zones?

To tackle it from another angle. Clear your browser’s cache and cookies and restart the browser.

There were, but not for the sites that I was unable to access. Since I have reinstalled the s/w things seem to be going smoother. Suspect when the s/w updated something became corrupted.

Thanks to everyone for the help/suggestions.