Network Issue

[mrwabam]

Hello All,

I just purchased a 16 port switch off newegg for my home network. I was told by the IT guys at work that I could plug the cable modem into the switch, without using a router, as long as I setup my linux box to act as the DHCP server. I assigned the linux box a static IP and told it to act as the DHCP server, but nothing on the network will connect to the internet.

Has anyone ever setup a network like this? What am I missing?

 

[JackMDS]

May be an authentication problem.

I.e. the Modem does not see the MAC number that is registered with the ISP.

:sun:

 

[mrwabam]

Is the only way to fix that to use a router though, a switch doesn't actually have a mac address does it?

 

[Cloud Strife]

I believe you still need to do NAT and route the traffic to an internal network, so a router is required.

 

[mrwabam]

Software in linux can't handle that? It has a router function off software, but I imagine I would have to connect the box directly to the cable modem and then to the switch...

 

[Cloud Strife]

Originally posted by: mrwabam
Is the only way to fix that to use a router though, a switch doesn't actually have a mac address does it?

Your ISP sees the MAC address of the first computer that's plugged into the switch. (in your scenario: modem --> switch --> clients) Wrong.

I assume you're using your Linux box to act as a router? Your configuration should look like this:

WWW --> modem --> linux (NAT, DHCP) --> switch --> clients

 

[mrwabam]

In that type of configuration, will the linux box slow the network down from www?

 

[Cloud Strife]

Originally posted by: mrwabam
In that type of configuration, will the linux box slow the network down from www?

Depends on how much bandwidth you get from your ISP. With modern 100Mb NICs, you shouldn't see a difference. Remember you'll need 2 NICs on the Linux box, one for external(modem) and the other for internal(switch). I recomend getting some cheap Intel 100Mb NICs; they use pretty low CPU resource.

 

[mrwabam]

I get 10mb down from ISP, have gigabit nic's in the machine.... That should be sufficient no?

 

[Cloud Strife]

Originally posted by: mrwabam
I get 10mb down from ISP, have gigabit nic's in the machine.... That should be sufficient no?

Plenty. Your modem is probably capped at 100Mb anyway. Which Linux software are you planning to use? I've heard great things from Astaro.

 

[JackMDS]

May be I am missing something, if there are other computers on the Switch, how do they get the Routing?

The Network should look like this, http://www.ezlan.net/network/router.jpg

You can put a Linux Box with double NIC and Routing software instead of the hardware Router, but never the less, it should look like the pic above.

:sun:

 

[Cloud Strife]

Originally posted by: JackMDS
May be I am missing something, if there are other computers on the Switch, how do they get the Routing?

:sun:

By having the router in front of the switch but behind the modem.

WWW --> modem --> linux (NAT, DHCP) --> switch --> clients

 

[JackMDS]

Originally posted by: Cloud Strife

Originally posted by: JackMDS
May be I am missing something, if there are other computers on the Switch, how do they get the Routing?

:sun:

By having the router in front of the switch but behind the modem.

WWW --> modem --> linux (NAT, DHCP) --> switch --> clients

Sorry Cloud your connection scheme is the right one, the post was directed to the OP.

:sun:

 

[Cloud Strife]

OP realized he will need a router if he plans to connect more than one computer.

 

[RebateMonger]

Originally posted by: mrwabam
...I was told by the IT guys at work that I could plug the cable modem into the switch, without using a router, as long as I setup my linux box to act as the DHCP server. I assigned the linux box a static IP and told it to act as the DHCP server, but nothing on the network will connect to the internet.

You can't hook up more than one PC to your cable modem unless you:

a) Are given multiple IP addresses by your Cable provider
or
b) You install a router of some sort

What am I missing?

Knowledgeable IT guys?
Or they either misunderstood you or you misunderstood them.

 

[mrwabam]

I'm thinking when I told them I was going to have my linux box handle the DHCP, they assumed I was going to have it act as the router :-(

Gotta pick up a second nic and i'll be good to go Till then, just using the old router

 

[Captante]

I actually did what your trying to do for years using Linux and/or a program called WinProxy under NT & Win2k, but these days quality routers are so cheap it seems kind of pointless & more trouble then its worth... I'd say just stick with the router unless you just want to play around & make your setup work,

 

[azev]

Originally posted by: mrwabam
In that type of configuration, will the linux box slow the network down from www?

IMO a linux box running iptables or other popular nat software should run better than most off the shelf soho routers.