Does Avast (for Mac) blcok ports (e.g., 8000)? How can I change that?

I am developing an application and I need to connect to localhost:8000. I am sure that something is listening at that port but it seems that firewall (Avast) prevents. Is it true? How can I change the list of open ports in Avast?

UPDATE: I removed AVAST and everything works perfectly.
Now, this is serious! I cannot have AVAST and work with ports, excepting that I find a way to manage the open ports. Any Help?

avast! for mac does not listen on port 8000 (unless you have changed the configuration file manually) and does not block it or redirect it in any way.