ack, looks good to me. -pritesh On Aug 30, 2013, at 10:02 AM, Ben Pfaff wrote:
> Signed-off-by: Ben Pfaff <[email protected]> > --- > FAQ | 34 ++++++++++++++++++++++++++++++++++ > 1 file changed, 34 insertions(+) > > diff --git a/FAQ b/FAQ > index 75d9007..5406e84 100644 > --- a/FAQ > +++ b/FAQ > @@ -250,6 +250,40 @@ A: The following commands configure br0 with eth0 and > tap0 as trunk > > ovs-vsctl clear bridge br0 mirrors > > +Q: Does Open vSwitch support configuring a port in promiscuous mode? > + > +A: Yes. How you configure it depends on what you mean by "promiscuous > + mode": > + > + - Conventionally, "promiscuous mode" is a feature of a network > + interface card. Ordinarily, a NIC passes to the CPU only the > + packets actually destined to its host machine. It discards > + the rest to avoid wasting memory and CPU cycles. When > + promiscuous mode is enable, however, it passes every packet to > + the CPU. On an old-style shared-media or hub-based network, > + this allows the host to spy on all packets on the network. > + But in the switched networks you'll find pretty much > + everywhere these days, promiscuous mode doesn't have much > + effect, because few packets not destined to a host are > + delivered to the host's NIC. > + > + This form of promiscuous mode is configured in the guest OS of > + the VMs on your bridge, e.g. with "ifconfig". > + > + - The VMware vSwitch uses a different definition of "promiscuous > + mode". When you configure promiscuous mode on a VMware vNIC, > + the vSwitch sends a copy of every packet received by the > + vSwitch to that vNIC. That has a much bigger effect than just > + enabling promiscuous mode in a guest OS. Rather than getting > + a few stray packets for which the switch does not yet know the > + correct destination, the vNIC gets every packet. The effect > + is similar to replacing the vSwitch by a virtual hub. > + > + This "promiscuous mode" is what switches normally call "port > + mirroring" or "SPAN". For information on how to configure > + SPAN, see "How do I configure a port as a SPAN port, that is, > + enable mirroring of all traffic to that port?" > + > Q: How do I configure a VLAN as an RSPAN VLAN, that is, enable > mirroring of all traffic to that VLAN? > > -- > 1.7.10.4 > > _______________________________________________ > dev mailing list > [email protected] > http://openvswitch.org/mailman/listinfo/dev _______________________________________________ dev mailing list [email protected] http://openvswitch.org/mailman/listinfo/dev
