Questions about setting up a SOHO network

Hello,

I’m new to networking and I’m thinking of setting up a SOHO network at home. One of my main intentions is to allow my friends to remotely access my files in my FTP sever. Well, here’s my basic plan for the network:
- Two workstations in my home.
- One File sever (running win2k, maybe)
Setting up a LAN may not yet a big problem as I see. There are many reference books in the stores that I can refer to. My big question is how do I link my LAN to the internet (so that my friends can access my file sever)? Currently I’m subscribed to dial-up broadband and my PC is simply connected to internet via an ADSL USB modem (attached with analog phone line connecting my home’s phone jack). I intend to use a router as gateway/firewall in my LAN but I don’t know how I should physically link the router to internet. Do I need to connect the router to a modem? Do I need to purchase special adapter or modem? I understand I need to obtain a Public IP address from my ISP but then I have no idea about the physical connectivity between the router and internet.

I sincerely hope anyone reading this can give me some ideas about setting up my network.

Many thanks in advance.

Hmm.. first off, will this be an 'always on' network.. in which case you will need to subscribe to some always on type of connection.. Cable.. or DSL.. or TI depending on your budget. Otherwise you can go with your existing setup.. your LAN will work all the time, and have internet access only when the dial up is connected... As i said it depends on what you want to do.

If you go with your existing setup, you dont need to put a router in there.. you just configure the machine which has direct internet access as the default gateway.. and set up the other machines to share its internet connection..

If you go the always on route then your provider will most likely give you all the required customer premises equipment like a router and once again you'll just need to sort out the firewall (which you should have i might add). The firewall is configured to route as well based on the rules..

as a simple diagram


internet --> providerrouter -->firewall-->yourlan

in this case your providers router just sends all traffic to the firewall (which will most likely be your gateway pc.. unless you want to put up a stand alone firewall and that will check its rules and accordingly forward to yourlan.

A word of advice, dont use the router per se as a 'firewall' while a router can perform what is known as 'packet filtering' using access-control lists, it does not have the capabilities to do proper firewalling.. and should not be burdened with such a task. Get yourself a good application firewall (they can be expensive though) such as Check Point or something..

Realise that security is a very real concern.. getting a network hooked to the net is an easy technical consideration.. ensuring that only those you want to access it can access it is a grey area that requires sitting down and listing what services you want to provide, and who you want to let in.

As a security person, i would make a recommendation that you isolate your public servers (such as the ftp file server) on a separate network from the firewall called a DMZ. This ensures that people accessing those services dont walk all over your other workstations and internal lan. thus the network would look like this

Internet
|
router
|
firewall

---

> DMZ with FTP server
|
Internal Lan

This site has some very thorough documentation on firewall topology.. hence the site name i suggest you go through it and choose a topology that suits you.

Hope that helped you out

Cheers,
Sahir.


ps. I live in India, where we don't understand the concept of broadband dialup dial up here means 56k modems.. nothing faster lol