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[Newbi] Can't get my network card to work

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This is probably something stupid but anywho here goes,


I have a sis 900-based PCI Fast Ethernet Adapter as a network card... it connect to my adsl modem. I'm running Mandrake 9.2 and when I go into the network configuration there is a network interface called eth0 but I can't get it to activate thus i can't connect my internet connection with pppoe because the card is down.... I also have a switch that mine and another computer are connected to which in turn connects to the modem contrary to what i stated(my bad)... Could someone please give me some steps on fixing this problem?



NeoPhreak >.<

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If you are connecting to your adsl modem through a NIC, why would you want to use pppoe??


Just set the card (mcc, network, lan) to work with dhcp instead of giving a static address, and (re)start the card/network.

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You don't need to put anything

just open the Mandrake Control Center ( need root psswd) (It may have changed name in 9.2)


go to the Network & Internet


and then configure the network using the "LAN " option and the "DHCP" option


the DHCP option will try to find you an IP address from the server. In your case, the ADSL modem will act as a server so you need to switch it on before to try to connect the PC.


hopefully this will help


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This depends on how it is set-up.

Assuming your (A)DSL modem allocates your IP and hostname....


1) It might be deliberately crippled by your ISP (if it came with the connection) to only allocate a single IP. This is quite common. The idea is to stop you using more than one PC and buy a commercial service of you want to.

(This can be bypassed but not that way)


2) It might only be capable of supporting a single PC.


(EITHER WAY its likely it will support only a single PC .... however we can share it BUT we'll cover that later)


Then you have authentification....

In theory you shouldn't need it. Your DSL line is locked to your line. Even if someone else gets your password/username it should be impossible for them to connect to your account from a different line.


However.... most home/SOHO ISP's do use it as a compatibility with dial-up or for other reasons best known only to them (perhaps its a windows limitation)


Theoretically under Linux (or any *nix) all you really need is a 'DSL modem' (which is actually incorrect in this context as it should be called a router) which takes your TCP/IP over Ethernet and 'routes' it to TCP/IP over ATM.



1) Some phone co's use TCP/IP OE (Over ethernet) for the last mile and bridge this directly to ATMat the exchange/sub exchange. Others don't.


In Paris it actually depends where you live!!!



So what aRTee is saying is theoretically correct, you shouldn't need pppoe....(point to point protcol over ethernet)

However, its not a perfect world and ISP's cater mainly for winBlows....


What you NEED to know (either by asking or experimentaiton or whatever) is do you have a pppoe line or pppoa line.


If your line is pppoe then you do need the pppoe packages.


2) You need to know if your DSL router/modem box allocates via DHCP (very likely) and further ... DOES it also supply its default route.


secondly.... pppoe expects authentification, in a parody of dialing up by modem.

For me ...using wanadoo I have a user name


and a password



If I use fti/qwertuiop@wanadoo.fr (it won't work, it doesn't expect the @wanadoo.fr)

But if you use sympatica in Canada they expect it (I know this becuase the default examples for pppoe uuse this)

Either way it needs to be 100% what is expects!!!


It then uses CHAP to pass this to the ISP server......

The router does two things....

1) When you plug it in and connect it to your DSL it connects to the ISP (which is dedicated to that line) and finds the DNS server and routes


2) when it supplies an IP by dhcp it exports this information to the box getting the IP.


At this point you have a single PC connected directly to the internet....



we talked about sharing the connection.....

Mandrake uses a approach I don't much like.... it uses a virtual NIC...

So if you have a card eth0 it creates for example an eth0:9


The plus side of this is it allows Windows like Internet connection sharing....

The negative side... if it goes wrong its a real problem to fix....


In theory you can have a eth0:1 and a eth0:2 with completly different IP ranges. IPTABLES then routes across them....However this is likely to play havoc with other config tools....or some applicaitons etc.

(like where you have to choose the interface from a drop down box)

but also its a bit of a mess and saves you 15$ on a seperate NIC if you don't already have one.....


The NEAT way is to have two NIC's and route across them....


One NIC just goes to the DSL modem/router (you only need an old 10 MBit)


This is set to dhcp and receives its IP address direct from the router/modem the IP it receives will be a REAL IP, that is it is a valid internet address. This is one reason the ISP's limit home users to a single PC.



The other NIC just goes direct to the switch....

This should have a static address in a non valid IP range (172. 192. or 10. )

These IP's are blocked on the Internet. Switches do not forward requests from them and you are therefore free to use them at home. It also gives you security. Noone can connect directly to this address becuase to all intents it doesn't exist outside your home network.


You then use IPTABLES to route requests across eth0 and eth1.

IPTABLEs is a bit of a job so most people use a front-end.

Mandrake comes with shorewall.


WARNING. If you select one config method in the Connection Wizard it is VERY difficult to get rid of it. (i.e. if you choose LAN you will never gain be given a chance to slect pppoe as your connection or visa versa without CONSIDERABLE messing about. (The easiest way I found was removing the NIC's and then reconfiguring)


Unfortunately .... Mandrake also do the virtual thing if you use pppoe.

The Mandrake config is 'strange' and undocumented.


Shorewall have some VERY EASY quick starts on theior website, which one depends how you want to use it.... dedicated server/router OR also as a normal PC and if you have another PC in a DMZ or not. (like a web/ftp server)



The shorewall docs are completely useless with the mandrake set-up UNLESS you are an expert (and just getting there is catch-22, its not actually that complicated its just you don't understand the concepts till its working)


Also SHOREWALL state explicitly.....

Do not connect your router/dsl modem to the same switch as you internal network other wise IT WILL NOT WORK and you will think shorewall doesn't work.


Doh... If you do the mandrake config with the virtual NIC's then actually it CAN work.... Once again it is a matter of if you try it and it just works then great else your in it up to your neck.


Shorewall can then be configured through WEBMIN, if you use their config files then its really easy and very well documented.


If you use the mandrake ones then it will look nothing like the documentation....




IMHO I'd try the shorewall setup and use 2 NIC's at this point you have one connected to the DSL and one to your switch and shorewall routes across them by using IPTABLES


You can set the other PC just to the same IP range and netmask as the eth1 interface which you made static....

i.e. if you chose with a mask of (A good choice we'll get to later) you can set the 'other C (windows OR linux) to be


You can go further....

If you have many PC's you can use dhcp to allocate the IP from the server/router


the interface is the DHCP server.

( is a good choice becuase it is one of the first IP's scanned when looking for a dhcp server and it means less config/faster allocation.

(mine is to all intents and purposes instantaneous)


If you do this and set your default routes to be exported then you just plug in another PC and set it to DHCP and it will get the routing and default gateway from the dhcp server.

If you statically allocate it then you need to tell it the default route ( and the DNS server (either your ISP or you can run your own local one)


Thats probably enough for now :deal:

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