Installing extra Lan Card

[Michael Smarsz]

-----Original Message-----
From: Alan [mailto:bigal at smartchat.net.au]
Sent: Friday, 21 June 2002 2:09 AM

>I have installed another Lan card into my Linux machine.
>I am using manual IP addresses.
>eth0         =  192.168.0.1       (255.255.255.0)
>Win2000 = 192.168.0.2
>Laptop    = 192.168.0.3
>eth1        =  192.168.0.4

What you have done is give your machine 2 interfaces on the same segment/subnet.  The subnet mask of 255.255.255.0 effectively means that all addresses from 192.168.0.0-192.168.255.255 are on that interface (local subnet).

Am I correct in assuming that you have 2 nics and no hub/switch, instead you are using 2 crossover cables (one form eth0 to win2k, the other from eth1 to the laptop)? As below

  Linux Box
   e0   e1
    |    |
    |    |
 win2k  laptop


If that is the case, eth1 will need to have an address from a different subnet (192.168.1.1 for instance) and so will the laptop (192.168.1.2).

Otherwise... you may be connecting as such


 Laptop    Win2k
   |         |
   |         |
   ----------- hub/switch
        |
        | e0
      Linux
        | e1
        |

and you are using the linux box as a router/firewall.  As above, eth1 will need to have an address from a different subnet.  The laptop/win2k boxen think that the 192.168.0.4 address is on that same segment and will not send the address out the gateway (eth0).

>Basically I don't know what I am doing so would appreciate some help.
>- I have configured 'eth1' using 'linux-conf' utility.

I hope I haven't added to your confusion... it makes sense in my mind ;)

>However I can't ping 192.168.0.4 from anywhere (even on the linux machine).

More than likely due to the routing tables associating that subnet (192.168.0.0/255.255.255.0) to the eth0 interface as it was probably brought up first.  Same as before, it is sending the request out the eth0 interface - check for activity lights when you ping.

HTH

Michael