Does a built in firewall on a router really keep your computer safe? Does that mean keeps safe from email virus, or websites? Or is it only keep you safe from direct attacks? I starting see I have a lack of understanding of how things work?
back in the days there was one way to get a virus lol seems things have gotton much more complicated I mean seems like you neeed twelve programs HIPS , Firewalls, Malware, anti virus, anti root kit,., complicated
Routers usually protect you well from outside sources. Reason being is that routers perform NAT translation.
So, when you have a computer behind a router that wants a website, it requests the website and the traffic hits the router. The router records the source IP address of the computer requesting the website and then replaces that internal IP with a valid routable external IP address., and when the traffic is returned from the web server, it sees the traffic and changes the IP address from the public IP that it was using, to the internal IP address of the machine which requested it.
So, if somebody sends packets that were unrequested to your IP address, you router will not have valid entries in the table and will drop those packets...thus protecting your machines.
However, if you do something stupid on a computer and initiate the connection, then the router is going to allow the return traffic to come back in and will deliver it to where it needs to go.
Moral of the story, the router won't protect you from yourself. You are still at risk from drive by downloads, facebook malware, email attachments and anything else that you might run.
NAT in and of itself isn't that secure, but most routers have a built in firewall which does the job nicely.
One thing I always do is test any new (or new to me) router against one or more testing sites to see if the router is truly transparent to unsolicited traffic. Any ports that I can't set to drop packets, I forward to x.y.z.250, which I reserve as a "black hole" on all my networks so there's never a device there to answer.
Anyway, I agree with pparks1's moral; any router will allow in pretty much any trouble you ask for.
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