network problem

[Roger Searle]

Hi . . .   I've put mandrake 9.2 on my notebook and can't get it 
communicating with my network (so no internet either).  The switch,  
cables and cards are all functioning as the desktop machines can ping 
OK, regardless of whether they are running XP or mandrake, and the 
laptop pings the network fine under XP.

Notebook IP address 192.168.0.9/255.255.255.0.  It has an onboard 
realtek RTL-8139 network module, the hardware control centre correctly 
identifies it and lists the 8139too module (driver?). 

I can ping localhost and ping the IP address on the notebook OK.  I 
can't ping further than that, nor can I ping the notebook from another 
machine (when the notebook is booted under linux).  I don't know what to 
do now, and don't want to give up!  Can anyone help me?

lsmod (among other lines):
8139too     17384     1     (autoclean)
ifconfig:
eth0
link encap:Ethernet HWaddr 00:00:E2:9C:46:72
inet addr:192.168.0.9 Bcast:192.168.0.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:0 (0.0 b)   TX bytes:0 (0.0 b)
Interrupt:3 Base address:0x7000
lo
Link encap:Local Loopback
inet addr:127.0.0.1 Mask 255.0.0.0
UP LOOPBACK RUNNING  MTU:16436 Metric:1
RX packets:72 errors:0 dropped:0 overruns:0 frame:0
TX packets:72 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:5188 (5.0 Kb) TX bytes:5188 (5.0 Kb)