[ovs-discuss] how to fliter arp requests from being forwarded to the gre ports

Jesse Gross jesse at nicira.com
Fri Aug 3 17:39:01 UTC 2012


On Fri, Aug 3, 2012 at 10:36 AM, Aishwarya <aishu85 at gmail.com> wrote:
> Ok. Thanks. Is there a way to check what ports a particular packet is being
> sent on? Like a capture functionality on a port? When I run tcpdump on br0
> interface, I sometimes don't see some packets going through that at all.
> For eg, in my setup I have 2 hosts. On host1, I have a vm1 ip
> 192.168.0.2/24. On H2 , I have a vm2 192.168.0.3/24. H1 AND H2 are connected
> through a gre port on br0. When I ping from vm1 to vm2, and capture packets
> on br0, I see that an arp request is being sent for 192.168.0.3, but I dont
> see the arp replies or the subsequent ping request replies go through br0 at
> all/(in tcpdump). But vm1 is receiving ping replies from vm2, and has the
> correct arp entry for vm2. Why am I not able to see these subsequent packets
> while capturing on br0?

br0 is not intended to capture all traffic on the bridge.  It's just
another port on the switch and you see the first packet because it is
a broadcast.  If you want to see traffic on a particular port you can
run tcpdump on there directly.



More information about the discuss mailing list