Network question

[Hacktarux]

I have 3 machines A, B, C.

A is connected to the internet and is using windows XP. It's sharing its internet connection with the standard win XP tools (it means it's using IP 192.168.0.1 and others computers should use DHCP to use this internet connection).

B has two network cards : the first card is connected to the A's network and is using DHCP to get his IP address. The second card is connected to C's network and is using a fixed IP address. B is under windows XP.

C is on a network that is using fixed IP addresses and that doesn't have internet connection.

Now my question, is there an easy way to let C use A's internet connection by only changing B's configuration ?

 

[Eagle]

I have 3 machines A, B, C.

A is connected to the internet and is using windows XP. It's sharing its internet connection with the standard win XP tools (it means it's using IP 192.168.0.1 and others computers should use DHCP to use this internet connection).

B has two network cards : the first card is connected to the A's network and is using DHCP to get his IP address. The second card is connected to C's network and is using a fixed IP address. B is under windows XP.

C is on a network that is using fixed IP addresses and that doesn't have internet connection.

Now my question, is there an easy way to let C use A's internet connection by only changing B's configuration ?

Well if B is sharing A's connection, then set up C to share B's connection. Right?

 

[Hacktarux]

no, if i setup a shared connection on B with XP, it'll automaticaly use 192.168.0.1 adress and will required C to use DHCP, that's not what i need...

now, i think i can't do that with standard windows tools, i'll need an external router software or something...

 

[PsyMan]

Unfortunately it's not so simple :\
The "problem" is that B belongs to two networks. A does not see C as part of the same network (and vice versa) and as a result C cannot use the internet connection of A. So in order to make C use the connection of A is to add C into the network that A belongs. In other words you can do it from C's configuration.
Sorry if this doesn't look too helpfull but I'm not aware of another way (and I doubt that I understood the problem correctly)...

 

[Hacktarux]

you understood the problem but the difficulty here is that i can't change C configuration easily...

 

[PsyMan]

Is it necessary not to change the configuration of A? Why not adding A in the same network as B and C?

 

[Gorxon]

Select the two network connections on B's computer and establish a bridge. (control panel -> network connections, select the two, right click and Create Bridge or whatever it's called in english XP). That should do the trick, but I could be wrong...both B and C should set automatic IP and get IP from A's DHCP.

Psyman:

For obvious reasons that wouldn't work (without bridging). They aren't on the same physical network, so you'd end up with two 192.168.0.x networks with no contact with eachother. And A is required to have 192.168.0.1 due to windows' way of handling internet sharing.

 

[Shin_Gouki]

the last suggestion sounds good, there was such a thing caled network bridge(i think it was to link 2 cards togetgher.. if that helps..?) if you have this already tried on B try the one above
wbr Shin Gouki

 

[PsyMan]

Select the two network connections on B's computer and establish a bridge. (control panel -> network connections, select the two, right click and Create Bridge or whatever it's called in english XP). That should do the trick, but I could be wrong...both B and C should set automatic IP and get IP from A's DHCP.

Psyman:

For obvious reasons that wouldn't work (without bridging). They aren't on the same physical network, so you'd end up with two 192.168.0.x networks with no contact with eachother. And A is required to have 192.168.0.1 due to windows' way of handling internet sharing.

Actually I had bridging in my mind but I wanted to know if Hac had the option to change A's configuration. The reason why I didn't suggested it was to avoid messing up with A or/and C. The solution you gave sounds good but I don't know if it works without messing with the other two. I bet Hac will tell us if it works

 

[Hacktarux]

ok i did it with nat32 except nat32 isn't free and is limited to an hour, anyone know a free equivalent ?

 

[PsyMan]

Most of the similar free programs have very restricted usage. I'm not aware of a free program that lets you do it. :\

 

[Gorxon]

Hack: did you read my post?

Also, didn't you have to change A's configuration to use NAT32? Afaik, it has to be installed on the computer with the internet access. Just curious...

 

[Hacktarux]

Gorxon: i can't set C to use DHCP because it's a homebrew made device.

I use nat32 on computer B. I set the card that's linked to A as the internet source and the card that's linked to C as the private lan card.

 

[Gorxon]

Even so, did you try bridging? I am not sure if you really need to have automatic IP on the C device...Just thinking it might be worth a try.

 

[Hacktarux]

yea, i've tried bridging, but if you do this, both network cards have exactly the same IP

 

[Malcolm]

well, if I'm reading this right (and I'd like to think that I am) this is what your network looks like:

/-----\
|  a  |
\-----/
   |
/-----\
|  b  |
\-----/
   |
/-----\
|  c  |
\-----/

If this is the case you'll need to setup IP forwarding in machine B, then set machine C's gateway to machine B's IP.

http://support.microsoft.com/default.aspx?scid=kb;en-us;315236&Product=winxp
Thats how to enable forwarding.

If you've done everything right you'll be able to ping A from C, and be able to ping google.com from C aswell

 

[Hacktarux]

interesting...

i've tried it but it doesn't work for some reason, nothing else should be done on B ?