Network defense

I am wondering if the firewall really works. In the summary, under Network Defense, it is always indicated: “The firewall has blocked 0 instrusion attempt(s) so far”. By comparison, in the older version of Comodo, after being online for 2 hours, the number of intrusion attempt indicated may be between 20 and 30 or higher. Is it a bug (most likely)? or does Comodo 4 make the computer really invisible to intruders?

What version are you using? Try setting the Alert Frequency to high under Firewall Behaviour Settings → Alert Settings (Firewall → Advanced).