Bizzare Linux behaviour #37

Tom Dunne

Continuing on from my thread last week regarding ifconfig, we had three machines (Red Hat Enterprise Linux, version 4) successfully re-IP addressed, thanks to some help I got on this forum.

Now, here's the strange bit - one machine is re-configured with a new IP address, powered off, moved, powered back up and does not generate any network traffic (i.e. the network card with the new IP address does not appear to work).

Until, that is, somebody logs in at the console as root. Immediately, the network admin can see network traffic and I can remotely log in.

Again, my background is databases, so I am not too clued in on the intricacies of Linux, but can anyone shed any light as to why this might happen?

Or where I might start to troubleshoot this? Presumably a good place to start would be in the .profile of root? Or could it be some power-saving thing where the network card is not activated until somebody actually does something?

GreenHell

So the machine is not pingable until someone logs in from a remote console?

Or by console do you mean, ssh,rsh or telnet?

Would you be able to copy and paste the contents of

/etc/sysconfig/network-scripts/ifcfg-eth0

and

/etc/sysconfig/network

If you can't, a good place to start troubleshooting would be to compare the settings in these files against a working machine.

Snowbat

In a default configuration, network startup is completely independent of the login process. If someone has put network configuration commands in /root/.bash_profile then they've put them in the wrong place (unless of course they *want* that behaviour).

Tom Dunne

GreenHell wrote: »

So the machine is not pingable until someone logs in from a remote console?

Or by console do you mean, ssh,rsh or telnet?

I mean directly at the machine itself. Once the person logs in at the machine, I can then log in remotely.

GreenHell wrote: »

Would you be able to copy and paste the contents of

/etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE=eth0
BOOTPROTO=none
HWADDR=00:14:5E:XX:XX:XX
ONBOOT=yes
TYPE=Ethernet
USERCTL=no
IPV6INIT=no
PEERDNS=yes
NETMASK=255.255.255.0
IPADDR=10.132.8.151
GATEWAY=10.132.8.1

GreenHell wrote: »

and

/etc/sysconfig/network

NETWORKING=yes
HOSTNAME=XXXX (contains the actual hostname)

cance

Tom Do an ls -l in the home directory of root as specified by snowbat and look for .bash_profile, i'd say he's close enough to the money.

Tom Dunne

cance wrote: »

Tom Do an ls -l in the home directory of root as specified by snowbat and look for .bash_profile, i'd say he's close enough to the money.

Actually, I did have a look in .bash_profile - nothing of interest in there.

I'll post it up in a while (need to fire up the VPN client again).

GreenHell

USERCTL=no

Should be set to yes I believe.

Snowbat

Also have a look in /root/.bashrc

ressem

When logging in locally at the machine, is the machine running the Gnome gui?
Some of the GUI network configuration utilities have shown strange behaviour on machines here in the past, changing the default settings to the settings it remembers.


Also a possibility, they aren't running "init 5" to start up the GUI after they log in? If the runlevels aren't correct the network service might not start by default.
Try:
chkconfig --list
Should give the list of services that start at each runlevel.
Level 3 is console, level 5 is GUI.

network         0:off   1:off   2:on    3:on    4:on    5:on    6:off

Also look at /var/log/messages for messages about eth0 starting up. See whether there are messages after the time at which the user logged in locally.