> After that I stopped the Iptables on the Host machine and I lost > external connectivity on my VM's. > The only way that I found that VM machine works again is restarting the > Host Machine. (Start Iptables service again on the Host didn't work) > > I'm using CentOS 6.2: 2.6.32-220.7.1.el6.x86_64 > The host's iptables is the default, I didn't add anything. > Why the Iptables is stopping the connectivity of VM when I stop it? If you don't have NAT rules in your firewall .. internal VM traffic that is not bridged won't get NATed and therefore can't reach the parent network.