[Nottingham] Network problems again...

[David Aldred]

I've just reinstalled Mandrake 10.0 on my main machine.   Some rather odd 
things had started happening - kdesu wouldn't run, konqueror and kontact 
tended to start once in a session but then hang if restarted, other oddities.  
Possibly related to forcing an update recently, but the oddities didn't start 
to happen for 24 hours after that!

Did the network setup for eth0 - the connection to the internet.  ifcfg-eth0 
reads:

DEVICE=eth0
BOOTPROTO=dhcp
ONBOOT=yes
MII_NOT_SUPPORTED=no
WIRELESS_ENC_KEY=""
NEEDHOSTNAME=no

And I can connect to the Internet.  

Then I try to set up the local wireless network.  Any time I set this up, it 
promptly kills off the internet connectivity (no ping responses, even to 
numeric addresses - and no error messages either).  When I set it up, the 
ifcfg-wlan0 file looks like this (without the deletions, of course):

DEVICE=wlan0
BOOTPROTO=static
IPADDR=192.168.0.1
NETMASK=255.255.255.0
NETWORK=192.168.0.0
BROADCAST=192.168.0.255
ONBOOT=yes
MII_NOT_SUPPORTED=yes
WIRELESS_MODE=Ad-hoc
WIRELESS_ESSID=<essid deleted>
WIRELESS_ENC_KEY=<key deleted>
WIRELESS_RTS=1536
WIRELESS_FRAG=1536

If I then delete the wlan0 interface, and restart the network and Shorewall, I 
have the usual Internet connectivity back. 

My first suspect was Shorewall, but I'm using the same configuration files for 
Shorewall that were working before reinstalling having backed them up before 
reinstalling.  It actually looks more as though once the wlan0 interface is 
set up, the machine is trying to use that for its internet connection, and of 
course failing.

Two other things which may be relevant:
- On a service network restart, 'Bringing up interface eth0'  reports a 
failure, but the interface still works.....
- This is the first install on this machine since getting NTL cable broadband.

What do I do now???

-- 
David Aldred