On 09/22/2010 02:49 PM, Daniel P. Berrange wrote:
On a recent installation of FC13, the filtering of IP/IPv6 using iptables/ip6tables traffic did not work since the proc filesystem entries /proc/sys/net/bridge/bridge-nf-call-iptables and /proc/sys/net/bridge/bridge-nf-call-ip6tables contained a zero each and no traffic went into the FORWARD chain. The patch below makes sure that if iptables or ip6tables are being used by the nwfilter driver that a '1' is written into the relevant proc filesystem entry so that the traffic goes into the FORWARD chain. NACK to this. We need to figure out how to make this filtering work with them set to 0. The change to set them to 0 by default is explicitly done for the benefit of virtualization, otherwise guest traffic gets blocked by regular host firewall rules which is not desirable. eg run system-config-firewall and block ssh
On Wed, Sep 22, 2010 at 02:19:31PM -0400, Stefan Berger wrote: port on the host, and you've blocked it on all the guests too :-(
The ssh port blocking for the host is a rule that goes into the INPUT table. That is independent of what libvirt does with the FORWARD table and this host rule would not influence the guest rules and vice versa. Traffic destined to bridged guests will NOT go through the INPUT table, only traffic from guests towards their own host will go through it. It depends on the version of RHEL/Fedora. Previous system-config-firewall would put the same rules on INPUT *and* FORWARD chain. The newer s-c-f
On Wed, Sep 22, 2010 at 03:35:54PM -0400, Stefan Berger wrote: puts a generic 'REJECT' rule on the FORWARD table. Either way, if you have bridge-nf-call-iptables=1, then all bridged guest traffic is significantly impacted. Setting bridge-nf-call-iptables=1 puts the system into working state so
On 09/23/2010 05:31 AM, Daniel P. Berrange wrote: that per-VM rules for the guest are correctly evaluated. The only difference is that some systems write a "1" into the proc filesystem entry automatically and on others this has to be done by the user. In the latter case I'd rather have it done by libvirt's nwfilter driver automatically when needed. Had I known that these proc filesystem entries exist, I may have set them a long time ago... The nwfilter driver also tries to set its own FORWARD table entries at the very beginning (first 3 entries) so that any subsequent reject doesn't apply. Stefan
Daniel