Many clients reported problem with kernel module necessary for iptables not properly loaded after we updated the underlying server with latest kernel on Oct 3rd.

Please note that the problem does not happen to VPS/VDS provisioned after the update. Please follow the following instructions to fix it:

***XEN MODULE KERNEL UPDATE***

Xen kernel module on each virtual machine (domU) need to be updated to match kernel version on the underlying server (dom0).

Error will be shown in your virtual machine when it is not matched, such as in your iptables. E.g.: iptables -L

-bash-3.2# iptables -L
iptables v1.3.5: can't initialize iptables table `filter': iptables who? (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.

Follow the following method to solve this problem:
(Please login as root first with command "su -" prior to executing the fix)

1. Check your virtual machine kernel version: uname -a

-bash-3.2# uname -a
Linux yourdomain.com 2.6.18-128.1.16.el5xen #1 SMP Tue Jun 30 06:39:23 EDT 2009 x86_64 x86_64 x86_64 GNU/Linux

2. Download kernel module which match your kernel version into your virtual machine:

(Please note that list of kernel modules is available at http://www.glicx.net/downloads/)

-bash-3.2# wget http://www.glicx.net/downloads/2.6.18-128.1.16.el5xen.tar.gz

3. Extract the file.
-bash-3.2# tar -zxvf 2.6.18-128.1.16.el5xen.tar.gz

4. Move the kernel module to /lib/modules/ directory.

-bash-3.2# mv 2.6.18-128.1.16.el5xen/ /lib/modules/

5. Load the module: depmod -a

-bash-3.2# depmod -a
-bash-3.2#

Now the problem is solved. You can check with iptables -L again.

-bash-3.2# iptables -L
Chain INPUT (policy ACCEPT)
target prot opt source destination

Chain FORWARD (policy ACCEPT)
target prot opt source destination

Chain OUTPUT (policy ACCEPT)
target prot opt source destination
-bash-3.2#

6. It is recommended to restart the server:

-bash-3.2# shutdown -r now

*********END********

Please report to support@glicx.net if the problem still exist after the update.