ADSL modem/Router configuration

**GNEEOT** · 01-25-2006, 10:07 AM

Can anyone help me with configuration of Small Office network.
I´ve got 10 windows workstations, 1 linux server, ADSL modem/router WESTELL Model 327W.
Now I using DialUp. I´m going switch to ASDL.
Can I use ADSL modem/Router like simple ADSL modem?
This modem has a lot of additional features: router, firewall, dhcp, dns, wireless, etc ...,
but I want use it like simple modem because I´m going to run dhcp, dns and some other services on my linux box,

**gr8rcake** · 01-25-2006, 11:58 PM

You should be able to disable the DHCP feature on the router to prevent conflicts with the Linux server.

I think that model has only 4 ethernet ports, so you may want to buy an extra switch for expansion. You'll need to plug in one port of the switch into the westell, and the rest of the servers into the switch and the remaining westell ports. That way, they'll all be able to communicate with one another and the Internet.

The default gateway for all the servers would be the IP address assigned to the westell on the office network. The westell will do DNS for internet IP addresses, but if you can set all the servers to use teh Linux server for DNS, so this shouldn't be much of a worry.

**GNEEOT** · 01-26-2006, 06:20 AM

My ADSL isn't yet activated. After finishing activating I'll try set it up the way you told me.(I've already got two 8 ports Switches), but I think I'll have some difficulties with IPTables configurations, because I'm new to linux and I don't know how to create right firewall IPTables script. Last time I used http://easyfwgen.morizot.net/gen/index.php for creating firewall IPTables script. There is field "Internet Interface: ", for DialUp it was ppp0. What is it going to be for new configuration?(I'm a little bit confused because with new configuration I'll have only one interface - eth0)
Sorry for, may be, stupid questions, but I'm really new for linux.

**gr8rcake** · 01-26-2006, 06:42 AM

I don't think you'll need to run iptables on the linux server.The DSL router will act as a firewall for you. Plug all the servers into the DSL router and it will protect them from the Internet.

If it were a regular modem, then it would make sense to make the Linux box an iptables firewall with one interface connected to the modem and another interface connected to your switches.

The router seems to have a web interface, so you shouldbe able to log into it with a web browser and set up your firewall configuration on it.

**GNEEOT** · 02-07-2006, 05:32 PM

Can I use router only to route all traffic to linux server and than it will go to other workstations. I need it because I want turn router's firewall off and set up firewall on linux server, because I can't set router's firewall right way (I don't want spend time to learn special router's language to define router's firewall rules right way)

**trickster** · 02-07-2006, 05:40 PM

Hi,

Let me see if I understand this:

You have an ADSL modem connected to/acting as a router. Then you have a server, acting as a router for your internal network. You should be able to do this. You just need to have another hub or something to connect the server to, and then the computers to the hub. That way, the computers would request data from the server, and the server can request it from the modem.
I hope I was not too confusing...

**Compunuts** · 02-09-2006, 02:56 AM

You need two NICs for your Linux box. Connect the first NIC card in your linux box to ADSL modem's Ethernet port. The second NIC to normal port of your switch. Your servers should be conected to the ports on the switch. I have the same setup. I don't really trust the modem's firewall.