Version 3 prevent all Internet access

I upgraded to v3 and it worked fine with setting up my remote desktop. However, it prevents all programs [Outlook Express, Firefox, etc] from accessing the Internet. I realize that a firewall is supposed to prevent hackers et al, but why prevent everything???

It looks like everything is set up correctly. For instance, OE seems to have permission to access the Internet, yet it can’t. I uninstalled v3 and went back to 2.4 and everything works fine again.

So, how do I get Comodo v3 to allow use of the Internet?

Make sure that when you rt. click on the taskbar icon, where it says “Firewall Security level” that you don’t have “block all traffic” clicked. Altho this is handy if you have broadband and want to play a game that is not online. If you click “block all traffic”, you have closed Comodo to in and outbound traffic. Just be sure to set it back after you’re done play the game.


I have found that with Comodo Firewall v2.4 that after intial installation, none of my programs would complete their access to the web. I had to tell Comodo to “Allow Fragmented IP Datagrams”. Everything worked after that. Where I live at, my DSL is on a “Reach” and I experience a high number of fragmented packets.
When I upgraded to Comodo Firewall v3, I experienced a similar Non-Responsive effect. Version 3, by default, allowed fragmented datagrams. So there was something else blocking my way. At the top of Comodo’s Diplay page there are 4 menu options: Summary, Firewall, Defense+, Miscellaneous. Choose “Firewall”. Under “Firewall Tasks” choose “Advanced”. Out of the four options available, choose “Attack Detection Settings”.
Under this menu you will find 2 tabbed headings. Choose “Miscellaneous”. Un-Check “Do Protocol Analysis”.
I have not had a problem with any of my programs accessing the web after unchecking this option.
I have found that if I leave the default settings Comodo sets at installation, nothing will work. You have to find the proper options that will work for you. The ones I have listed here today have worked for me. You may find that you will have set “Defense+” to the “disabled mode” and just run the firewall only until fixes are made.
The way there is: DEFENSE+> ADVANCED> DEFENSE+ SETTINGS> GENERAL SETTINGS> Slide the control bar to “Disable” and restart your computer.

Thank you for all the suggestions. Unfortunately, none of them worked. There was nothing blocking the internet anywhere. Everything was green and supposedly good to go. Nonetheless, all access to the internet was blocked tight. I could use my laptop as a remote desktop, so the network was okay. Just no internet access.

What does your firewall event log say is being blocked? There should be a block of TCPs to port 80 from each of your applications, unless you are using a proxy. Do you have any global rules? Is your browser using the Predefined Policy for web browsers? Do you see the block of a UDP to port 53 in your log? I seem to recall that there was an “allow DNS” rule missing from the “web browser” policy at one time.

On my wife’s laptop we updated to Comodo v3 and she cannot get an IP address from my router anymore, wireless or wired. The router was not seeing requests and uninstalling Comodo v3 solved the problem. I don’t have time to fool with advanced settings or trying to explain to my wife how this is supposed to work (or have her guess). If I do see a real solution on here, maybe we will go back.

Don’t know why Comodo would be blocking DHCP requests, but without a log it’s hard to tell. For DHCP , the rule is allow/UDP/in:out/any/any/68,67/67,68 unless you want to refine it just to your router. But I haven’t read of anyone else being DHCP blocked, so it may well be some other problem. If you try CFP3 again post what the actual blocks are from the log. Are you using Comodo 3 also?

To be more accurate, the DHCP was somewhat working, the router assigned my wife’s PC an address, but the laptop timed out and got the standard 169… address listing. Multiple reboots did not help, but removing Comodo did the trick.

That was one fo the problems…there were NO log files; there was nothing listed in the Events; no activity, nothing…zero, zilch, nada. When I first installed it, I got a message that should have warned me. Comodo said that I had McAfee and ZoneAlarm installed. I have neither one installed or even on my computer at all!!! The port wizard was blank…it was as though I had no ports. I tried everything I could think of, but the events page stayed blank, no activity ever appeared, with the exception of the network, but not the Internet, and there were no log files anywhere to be seen. And, no, I don’t use a proxy.

Comodo v3 effectively shut off my Internet access…it was as though I was not even connected to the Internet although it could “see” my laptop which is connected by network via a router. So the LAN was no problem, but it was like there was no internet connection. Even after I shutdown Comodo v3, I still could not access the internet. I was not able to access it until I uninstalled Comodo v3.

I am now using 2.4 which works fine and has none of the above-mentioned problems.