Turning A Linux Box Into A Broadband Router

[Torin_Darkflight]

Networking is one of my weak points. Linux is also one of my weak points. Combine networking with Linux, and I am hopelessly lost.

I have an old-ish computer I cobbled together using various parts I had laying around (Celeron 900 with appropriate motherboard, 32MB RAM, 4GB harddrive, CD, floppy, etc). Now, I am wanting to turn this computer into a wired/wireless router to connect every computer in the house in preparation for a high-speed internet connection we shall hopefully be getting in the semi-near future. A secondary goal is to also use the router to network all of the computers together for file/print sharing purposes.

I figured since I already had the hardware, I wouldn't have to buy anything. Now all I need is the software. This is where Linux comes in. The problem is: I know almost nothing about simple networking under Linux, let alone something as complex as making a router. Part of the problem I believe lies in the complexity of this project. I'm not making a simple pass-through firewall (SmoothWall and the like), I'm making an actual router with multiple ports and connectors (Although firewall functionality would also be nice to have). The Linux box itself contains five network adapters: four wired and one wireless.

One of the wired NICs is an older Realtek (Exact model unknown at the moment) 10mbps ethernet adapter. This is the one that will be connected to the internet. The remaining three NICs are all 100mbps, they're the same brand and same model (Intel Pro-100). These three NICs will be on the LAN side, the rest of the computers in the house will connect to them (One port per computer, just like a real router). All four wired NICs are PCI cards.

The wireless adapter is a Zonet ZD1211U USB 802.11b WiFi adapter. This I want to use to allow my laptop to connect to the internet, and the rest of the computers on the LAN.

Anyway, here is a rough diagram of what I am wanting. Forgive the crudity of this drawing:

1-The Realtek NIC connects the Linux box to the internet

2-The three Intel NICs connect the other desktops to the Linux box/router (There's only two other desktops right now, the third NIC is there in case I ever need to add another system to the wired LAN)

3-The USB WiFi adapter connects my laptop (As well as any other computers I make wireless-capable) to the Linux box/router

Every computer on the LAN (Both wired and wireless) should be able to access the internet simultaneously, and also each other for file/print sharing. So, there also needs to be a bridge (I think that's the right term) connecting the wired and wireless segments together.

So, I am here seeking recommendations, instructions, anything to help me with this task. I have already searched Google, but I couldn't find anything that seemed to fit what I am wanting. Most of them dealt with just the firewall aspect, like SmoothWall, which only works with two network adapters, not five. Others required the computers to be connected to a separate hub, which in turn is connected to the Linux box, so on and so forth. That's not what I want. I want all of the computers to be connected directly to the Linux box. I want the Linux box to operate as the firewall (If possible), router, hub and wired/wireless bridge, all in one, no extra external boxes.

I really need help with this little adventure (If you can call it that). When replying, please try to be as clear as possible. A specific step-by-step would be most desired if possible.

I appreciate any help you can provide.

[TheTerrorist_75]

Here's a few links to creating a Linux router using GNU Zebra.

Use Zebra to set up a Linux BGP/OSPF router

Those that understand Linux (not me) would know much more, but this should give you an idea.

[iccaros]

I use monowall (BSD not Linux) and devils-linux (devil as in the BSD mascot).. both make good firewalls and both have wireless support.

but if you want to learn linux as a goal ... you need to learn iptables.. then any linux/bsd distro can be a firewall..

if you want it up fast and work monowall I think is the best.

[iccaros]

Every computer on the LAN (Both wired and wireless) should be able to access the internet simultaneously, and also each other for file/print sharing. So, there also needs to be a bridge (I think that's the right term) connecting the wired and wireless segments together.

you will need two wireless cards set to diffrent channels (one to server ips and a connection and one to bridge)

need to learn iwconfig command..

agian monowall and devil-linux should help..

here a a good resource(instrutinos for red hat but easy to use on any distrobution)

http://www.roseindia.net/linux/linux-firewall.shtml

[Torin_Darkflight]

It appears that Monowall is a firewall only, not a full router that supports five network adapters simultaneously with multiple computers connected directly to it. Looking closer at Devil Linux leads to the same conclusion, it's not a multiple-port router, it only works with two NICs. Remember, the software must support four wired NICs and one wireless USB adapter, no less, with NO EXTERNAL HUB REQUIRED. The core function of the box is going to be a four-port wireless router. Firewall functionality is not mandatory. I want it to be the Linux box and ONLY the Linux box.

What exactly do you mean by me needing two wireless cards to bridge it to the wired LAN? On Windows I'm able to bridge wired and wireless together using just the USB adapter, nothing extra. The only reason I'm not looking for a Windows solution here is because Linux is supposed to be better and more stable for networking purposes.

When replying, please speak using terms and procedures that someone who has just sat down at Linux for the first time could understand.

[iccaros]

really, I have 5 nics and two wireless in my devil-linux and 3 nics and one wireless in monowall.

[TheTerrorist_75]

iccaros is correct. You need to understand iptables.

YoLinux: Using Linux iptables or ipchains to set up an internet gateway / firewall / router for home or office

Devil-Linux 1.0: Firewall/Router Distro

Edited April 26, 2006 by TheTerrorist_75

[iccaros]

What exactly do you mean by me needing two wireless cards to bridge it to the wired LAN?

the term bridge means to connet two wireless access points to each other, a access point does not connect like a client to you must bridge the networks..

if you are just going to allow wireless connections (making your system the acsess point) then only one card is needed and it is put on the same subnet or has a gateway assined..

This is network 101 and has nothing to do with linux.

[larry_f]

Networking is one of my weak points. Linux is also one of my weak points. Combine networking with Linux, and I am hopelessly lost.

I have an old-ish computer I cobbled together using various parts I had laying around (Celeron 900 with appropriate motherboard, 32MB RAM, 4GB harddrive, CD, floppy, etc). Now, I am wanting to turn this computer into a wired/wireless router to connect every computer in the house in preparation for a high-speed internet connection we shall hopefully be getting in the semi-near future. A secondary goal is to also use the router to network all of the computers together for file/print sharing purposes.

I figured since I already had the hardware, I wouldn't have to buy anything. Now all I need is the software. This is where Linux comes in. The problem is: I know almost nothing about simple networking under Linux, let alone something as complex as making a router. Part of the problem I believe lies in the complexity of this project. I'm not making a simple pass-through firewall (SmoothWall and the like), I'm making an actual router with multiple ports and connectors (Although firewall functionality would also be nice to have). The Linux box itself contains five network adapters: four wired and one wireless.

One of the wired NICs is an older Realtek (Exact model unknown at the moment) 10mbps ethernet adapter. This is the one that will be connected to the internet. The remaining three NICs are all 100mbps, they're the same brand and same model (Intel Pro-100). These three NICs will be on the LAN side, the rest of the computers in the house will connect to them (One port per computer, just like a real router). All four wired NICs are PCI cards.

The wireless adapter is a Zonet ZD1211U USB 802.11b WiFi adapter. This I want to use to allow my laptop to connect to the internet, and the rest of the computers on the LAN.

Anyway, here is a rough diagram of what I am wanting. Forgive the crudity of this drawing:

1-The Realtek NIC connects the Linux box to the internet

2-The three Intel NICs connect the other desktops to the Linux box/router (There's only two other desktops right now, the third NIC is there in case I ever need to add another system to the wired LAN)

3-The USB WiFi adapter connects my laptop (As well as any other computers I make wireless-capable) to the Linux box/router

Every computer on the LAN (Both wired and wireless) should be able to access the internet simultaneously, and also each other for file/print sharing. So, there also needs to be a bridge (I think that's the right term) connecting the wired and wireless segments together.

So, I am here seeking recommendations, instructions, anything to help me with this task. I have already searched Google, but I couldn't find anything that seemed to fit what I am wanting. Most of them dealt with just the firewall aspect, like SmoothWall, which only works with two network adapters, not five. Others required the computers to be connected to a separate hub, which in turn is connected to the Linux box, so on and so forth. That's not what I want. I want all of the computers to be connected directly to the Linux box. I want the Linux box to operate as the firewall (If possible), router, hub and wired/wireless bridge, all in one, no extra external boxes.

I really need help with this little adventure (If you can call it that). When replying, please try to be as clear as possible. A specific step-by-step would be most desired if possible.

I appreciate any help you can provide.

I hope you get this message. It is a bit late to be posting, but maybe it will help someone else looking to setup this type of box. Here is a link to ipcop. you can get everything you need here. http://www.ipcop.org/ . Here is a howto for setup. http://www.howtoforge.com/perfect_linux_firewall_ipcop

have fun.

[hitest]

I agree with iccaros,

Our Sysadmin set-up monowall at the office and it is robust, secure, and stable for the 160+ computers on our LAN.

[shanenin]

I have a friend who really likes pfsense. I think he said it is very easy to set up. This creates a very durable router.

edit added later//

I just noticed they have a high, 128mb, ram requirement. It may not run well with 32mbs