ports no more stealth

Hi everone,

CIS 5.12.5625.xx
firwall in safe mode
Recently changed my modem router to D-Link2750LU old went kaput .just checked on GRC by turning off router firewall,
results showed all ports closed not stealth but port 21,22,23,80,139,445 open, NEtBIOS, file & printer shring is turned off on public interface.
-running stealth wizard does not changes the result.
-running diagonistic check produced the same result.
-turning comodo firewall off & windows firewall on produced the same result.
-Turned off the tenet,FTP, HTTP services on LAN side in router no result
-turning ON router firewall makes me pass GRC test excepect port30005 TR-069

I know it is the best forum to ask help any guess…



Simply turning off the router firewall does not mean GRC tests your computer, I assume you are still behind NAT? So if you turn off the router firewall it will still test the router, it just doesn’t have the protection of the firewall.

Thank you for reply
You can not turn off NAT in PPPoE it is set by ISP.
-Problem is still there .how to close ports.
-Turning off services (telnet,ftp,http,)options on LAÑ side in router has no effect.
As turning ON firewall in router make port stealth

It also implies Firewall is logically after NAT in router
Comodo or any should block incoming connection "

CIS can block incomming connections, however it can not block the GRC test because the GRC tests your router and not your computer so the CIS doesn’t even see the traffic and hence can not act on it. CIS does not have physical nor logical access in the network to block the GRC test if you are behind a router with NAT on and if you haven’t made your computer into the DMZ.

Comodo firewall does block the GRC test.
Check the box for "log if firewall rule is fired"in global settings for incoming blocked connections and comodo does block the GRC probe.

If you have a router and you are behind NAT then it shouldn’t matter since GRC will report what the router says even if your computer receives packets which are blocked.

Edit: Just tested this.
Router Firewall ON - CIS Firewall ON : All service ports stealth.
Router Firewall ON - CIS Firewall OFF : All service ports stealth. (Same result as above)
Router Firewall OFF - CIS Firewall ON : Port 23 open even though global firewall rule which says block all incoming, same with port 443. Most of the rest are closed, some are stealth.
Router Firewall OFF - CIS Firewall OFF : Same result as above.

Router Firewall ON - CIS Firewall ON - Router forwards port 26334 to my internal IP address : Port is seen as stealth.
Router Firewall ON - CIS Firewall OFF - Router forwards port 26334 to my internal IP address : Port is seen as open.

Here you see what I mean, in order to actually test your computer you must bypass the router by for example forwarding all your ports or turning off nat/router part which means it is just a modem which means it just passes through everything without filtering it. I haven’t used DMZ mode ever but I’d assume that would also work.

Edit 2: Yup DMZ works too.

will see after port forwarding or redirecting traffic into DMZ.
thanks for elaborate testing, it will definitely help a lot in understanding.