Sharing Files behind a router

[Centropolis]

According the tutorial at this following link,

http://www.homenethelp.com/web/howto/net.asp

if I have a hub or a switch between my broadband modem and my computers connected to the hub/switch, and I enable file sharing....it may give access to anyone on the internet my shared folders. It says it will be okay if I am behind a router or a hardware firewall.

My question is, I do have a braodband router between my computers and my modem. However, I've setup my computer in the DMZ straight into the Internet without any protection from the router. I want to share my files with other computers on the LAN, can I still use this tutorial? Or will I be sharing my files with the Internet?

 

[HoLoCroN]

What kind of router do you have? (Make and Model #)

According to the tutorial, if you don't have a DSL/Cable Router you SHOULD NOT plug the modem directly to a hub.

If you DO have a router (Most of the time for the DHCP setup, making sharing the internet connection with multiple computers as easy as plugging the cable in) AND a firewall program installed on your system, You don't have to worry too much about your files being broadcasted to the world.

Most of the time, routers come with a buit in NAT Firewall, that would be your first level in what should be a multi-tiered firewall setup. (NAT Firewall, Software Firewall such as Zone Alarm or NIS)

Just make sure (If your router has this capability) that your firewall is enabled and that IP Forwarding is disabled. This will for the most part, limit outside traffic communication just to your router! All computers will connect to the internet through the router.. instead of directly with the cable modem.

One of the few reasons you would have IP Forwarding enabled is if you had a web server behind your router NAT firewall. If you don't have an internet server (IIS,Apache) then I recommend disabling the IP Forwarding on your router.

 

[Centropolis]

What kind of router do you have? (Make and Model #)

According to the tutorial, if you don't have a DSL/Cable Router you SHOULD NOT plug the modem directly to a hub.

If you DO have a router (Most of the time for the DHCP setup, making sharing the internet connection with multiple computers as easy as plugging the cable in) AND a firewall program installed on your system, You don't have to worry too much about your files being broadcasted to the world.

Most of the time, routers come with a buit in NAT Firewall, that would be your first level in what should be a multi-tiered firewall setup. (NAT Firewall, Software Firewall such as Zone Alarm or NIS)

Just make sure (If your router has this capability) that your firewall is enabled and that IP Forwarding is disabled. This will for the most part, limit outside traffic communication just to your router! All computers will connect to the internet through the router.. instead of directly with the cable modem.

One of the few reasons you would have IP Forwarding enabled is if you had a web server behind your router NAT firewall. If you don't have an internet server (IIS,Apache) then I recommend disabling the IP Forwarding on your router.

I have the DLink 604 router. I understand that my router should provide firewall protection but I've setup up me computer so that it's not straight through to the Internet. In the DLink setup...t's called the DMZ. I think it means that if I setup my IP address as in the DMZ, it means that it's not protected by the firewall at all?!

In that case, I should NOT use this tutorial to share my files right?

 

[ekÆsine]

why are you putting the computer on DMZ? that is asking for a truckload of trouble. if you have no software or hardware firewall on DMZ most likely you will get a virus or trojan within 10 minutes. scan your whole system for virus if you did.

yes you can share files on DMZ because you are still connected to the internal network since your router is also a switch.

 

[mikesgroovin]

Users across the net WILL NOT be allowed to access your shares in your situation. You have to be servicing a module of IIS for this to happen....which I seriously doubt you do. Simple File and Printer sharing doesn't work across the net like this. It's all based on routing. So, for example, from within the LAN and from another computer you can type in the UNC path for the computer and shared resource (\\COMPUTERNAME\SHARENAME). But from the outside, you won't be able to use this type of path, or even IP address to access your shares. Doesn't work that way. Even if they knew your external IP address (Internet Address), network shares would not be visable. It's all based on what ports you have open to the net (This is where it gets to what ek was saying). So people, using what port numbers you have open, would be able to access your computer, and then you are at risk with getting a virus or a data-miner. I think that the person that developed this site is just trying to cover his/her own ass.

-Mike

 

[Centropolis]

why are you putting the computer on DMZ? that is asking for a truckload of trouble. if you have no software or hardware firewall on DMZ most likely you will get a virus or trojan within 10 minutes. scan your whole system for virus if you did.

yes you can share files on DMZ because you are still connected to the internal network since your router is also a switch.

The reason why I am putting my computer in the DMZ is because I am using BitTorrent and it is MUCH faster downloading if I am not behind a firewall. I know I am kind of in trouble but I haven't had any problems YET! I hope my Norton Anti-virus is working fine.

I know I CAN share files behind a router but I am worried that if I am not behind a firewall (becasue I am in the DMZ), if I enable file sharing....in theory will it be VERY easy for ANYONE on the Internet to get at my harddrives? Cuz that's what the tutorial I' read kind of said...or maybe I am reading it wrong?!

 

[ekÆsine]

you don't need to use DMZ. to use bittorent and get fast downloads just read your router manual about how to open a port. this is called port forwarding. in bittorrent put this port number into the settings options. now you will have full speed downloading

 

[HoLoCroN]

I agree with Mike, not having a firewall installed (SW or HW) on your network does not mean that your shares are being broadcasted to the whole world.

That is not the risk that you are in at the moment. The risk you are in is..... Opening a web page that has a java script that copies a trojan or some other type of backdoor software (Can you say "Back Oriffice"??) Onto your system and your virus definition files are out dated (Or.. the bug is too new to be picked up by your AV software) and THEN.... Your computer has been compromised.

That trojan software will use your open ports to send Mr. Hacker all the info he needs to proxy to your computer.... Steal a million bucks from the federal reserve... and leave you to blame...

Well, maybe something as drastic as that won't happen but you are potentially at risk when not prepared for todays highly skilled malicious coders just waiting for someone like you to come to them...

Leaves allot to think about.

 

[ekÆsine]

man that happened to me last Tuesday, it really sucks

That trojan software will use your open ports to send Mr. Hacker all the info he needs to proxy to your computer.... Steal a million bucks from the federal reserve... and leave you to blame...