From: Stefan Berger<stefanb linux vnet ibm com>
Subject: Re: [libvirt] Network Filter not working on RHEL-6
To: "Shi Jin"<jinzishuai yahoo com>
Cc: "libvirt Redhat"<libvir-list redhat com>, jinzishuai gmail com
Date: Wednesday, March 2, 2011, 11:36 AM
On 03/01/2011 06:03 PM, Shi Jin
I have been testing the Network Filter  feature of
libvirt with KVM on RHEL-5.6 and RHEL-6. On RHEL-5.6, it
works well except the $IP variable is not supported thus
cannot use the clean-filter.
The major problem I found on RHEL-6 is that the
iptables rules introduced by nwfilter does not prevent any
traffic. The problem is that all traffic going to the VM
virtual NIC interface goes through the INPUT chain of the
iptables instead of the supposed-to-be FORWARD chain (this
is what the nwfilter rules are working on) so that none of
the rules have any effect.
I am not sure whether this is a libvirt problem or
iptables problem. But it seems to me that changing from
RHEL-5.6 to RHEL-6, the network traffic works differently.
Has anyone had similar experience? Any suggestion or
comments are welcome.
The libvirt log file probably would tell you something like
To enable iptables filtering for the VM do 'echo 1>
Try that command and it should work. It became necessary
due to changed
default Linux kernel behaviour.