XP Firewall, Internet sharing through router, and file sharing

[PSUlion01]

Recently redid the home LAN with a Linksys router (used to use ICS with the cable modem shared through a host computer). WinXP enabled the firewall protection in the network card properties by default, but when enabled I can't access the other computers on the LAN and share files. As soon as I disable the firewall I can share and access the other computers.

The router says something on the box about having a firewall built-in, but will this be enough to protect me? Can I enable the XP firewall and still share between computers on my LAN?

I'm trying to redo my network from the bottom-up, making it more secure in the process. Will eventually switch the wired router to a wireless (for my new laptop) but that'll be in a few months.

Also, when I ran the XP wizard to configure the network, I selected the option depicting all computers connected through a HUB, with the HUB directly connected to the cable modem. I was correct in doing this, yes?

Any guidance would be greatly appreciated!

 

[JackMDS]

WinXP ICF is only a partial Firewall, it does not add anything to the Router's NAT-Firewall.

On Firewalls.

All Entry Level Cable/DSL Routers by default are NAT-Firewall. Some have additional protection like Statefull Package Inspection (SPI).

When you use few computers to share one Internet connection, the information that comes from the Internet needs to know to which computer it belongs. The main function of Cable/DSL Router is to Route the Internet signal to the requesting computer. This function is called Network Address Translation (NAT).

As result information that comes from the Internet and was not requested by one of you LAN's computers (e.g. hacking attempts) does not know where to go, and it is blocked, hence NAT Firewall. Actually the NAT-Firewall does not do any thing active concerning the content and the nature of the information, it does not know what to do with the none requested Info. that is coming in and blocks it.

Additional methods employed by more sophisticated Firewalls (like using SPI) actually inspect the content of the packets and can block it according to a set of given rules.)

When you are connected to a Website or downloading files, a lot of junk can get to your Hard Drive. Since you requested the pages for the site the NAT Firewall will not block what comes in from this page. If the "Site Keeper" loaded the page with "Junk" it will get to your computer.So you have NAT-Firewall but you can end up with Viruses, Zombies, Trojan etc. "Dished" to you by sites that you visited on your own volition,

Since the NAT-Firewall blocks only Incoming, any communication initiated from any of your LAN's computers will go out to the Internet, and will be answered. As a result programs calling home, spywares, "zombies" etc. can communicate freely in lieu of the NAT Firewall. You will not be aware of these activities unless you monitor the communication locally with a software Firewall.

Most decent software Firewalls will alert you to existence of this communication, and will allow controlling it in various ways.

In addition using programs like Ad-ware, and Trojan Blocker, will further secure the Network.

How much safety you need? It is a matter of Surfing habits and personal preference?

Link: Basic Protection for Broadband Internet Installation.

Link: What is the Best Firewall?

 

[martind1]

let me sum this up. since youa re a small network and you ahve a firewall on your router, go ahead and turn off the xp firewall. You could just open the ports on the xp firewall to allow file sharing, but for ease you can just turn it off.

or do the research and figure out what ports you need to open up on the xp firewall.