Hi Dazedand,
A few answeres from; not a pro.
Quote:
How can some packets get through if they aren't in response to a request
Your router is continualy sending out requests.
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What value does the firewall function have? It may keep the amateurs out but isn't it the pros we really need to fear
No it is all the worm activity and scriptkiddy's (not pro's). That you nead protection from. Unless you have a network that will be of interest the afor mentioned will be of more interest to the pro's.
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When I do an online port scan the sites always see my real IP and ask me if this is correct. I thought that the NAT (or whatever) function of the router kept me hidden and broadcasted only the routers IP or some proxy type of address
The Routers ip address is you true addess, your pc's address is hidden from the outside world by the router. You accsess the internet through the router which acts as your gateway.The address the router is at is asigned by your isp. As the router is Nat,ing your pc's address all the outside world sees is your router and not your pc.
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Finally some scanning programs seem to find a few open ports even with routers firewall and Zone Alarm running. One more thing why do so many ports seem open or at least listening....it just seems to be a loosing battle
If your router is acting as a firewall, online scans should not see open ports. Your comp on the other hand may have lots of open ports, depending on what aplications you have running. There will always be some ports open otherwise you will not be able to do anything online.