On Monday 19 December 2005 1:31 am, Toshi Esumi wrote:
The most important aspect of putting a device between your PC and the modem is that the device takes care of NAT(Network Address Translation) from/to a public IP to/from private IPs. In case you hook up the modem directly into your PC, your PC needs to have a public IP address assigned by Comcast, let's say 24.120.10.121, which is accessible from anywhere around the world. That's why you HAVE TO set up Firewall on your machine. On the other hand, if you put a device in-between, the device MUST have two interfaces (could be logical interfaces): one has 24.120.10.121 and the other has any private IP address, let's say 192.168.1.1/255.255.255.0. And your PC can have one of IPs in the same subnet, 192.168.1.2-192.168.1.254. It can be assigned via DHCP from the device or assigned statically/manually. This case, everybody outside can try accessing the device using 24.120.10.121 but can't access your PC because of NAT on the device. Of course, if a hacker found a way to break into the device, the hacker can have many ways to attack your PC, like setting up port mapping or whatever. But the chance the hacker or viruses can attack your PC is much less than you hook up the PC to the modem. Needless to say, if you need or decide to add another PC, it would be much easier than installing another NIC into your PC to connect your second PC.
Well said. It explains just why a router is worthwhile even if there's only one computer connected to it. They're not expensive, they're very easy to install even with little knowledge, and they simplify matters enormously if you ever want to hook more than one computer to the Net. I've often wondered, though, how strong the router firewall is. Routers can be configured to allow settings from outside, though I don't think that's the default on the typical Linksys or Netgear. It's also a good idea to set the password to a non-default value, although I don't know whether that's really necessary if outside access is blocked. Anyone know the story on router hacks? Paul