kernel.randomize_va_space changes led to dead eth0

patitoconejita · 11-25-2007, 08:10 PM

Hello Debianers,

An external GIS software package (Seadas) that runs with IDL apparently needs to have kernel.randomize_va_space set to 0, according to the developers. They recommended doing:

/sbin/sysctl -w kernel.randomize_va_space=0

and reboot if the variable was set to 0 (it was in my case). However, now eth0 is no longer there, since ifconfig only shows the lo interface is running, so I have no internet anymore. I tried setting the variable back to 1 with the same command and reboot, but eth0 (hence internet) are still dead. Any help please? I'm baffled!

Dutch Master · 11-25-2007, 09:24 PM

Presumably, 'cause you're posting in the Debian section, you're on Debian. But Ubuntu and other Debian derivatives are similar.

Check if the file /etc/network/interfaces contains an entry for eth0. Mine (on Etch, for DHCP) looks like this:

Code:

# The primary network interface
allow-hotplug eth0
iface eth0 inet dhcp

patitoconejita · 11-25-2007, 10:01 PM

Quote:

Originally Posted by Dutch Master

Presumably, 'cause you're posting in the Debian section, you're on Debian. But Ubuntu and other Debian derivatives are similar.

Check if the file /etc/network/interfaces contains an entry for eth0. Mine (on Etch, for DHCP) looks like this:

Code:

# The primary network interface
allow-hotplug eth0
iface eth0 inet dhcp

What do you mean? I know I'm posting to the Debian category; this is in a Debian unstable system. Anyway, I did check that file and eth1 (I was wrong about it being eth0) was there as it was before. I don't know what exactly /sbin/sysctl -w does, but it messed up my network configuration big time. I tried dpkg-reconfiguring -a (all packages) and still no fix, and I also reinstall the linux-image kernel package 2.6.22-3 amd64 assuming that variable might get reconfigured, but it didn't help. What a nightmare.

Dutch Master · 11-26-2007, 07:02 AM

You didn't say you're on Sid. :P Anyway, try the ifup command to see if the network comes up. If it fails you have a serious issue. However, running Sid expects from you that you know how to solve a problem when (not if) one occurs. Did you read the man-page for sysctl?