[ovs-discuss] OVS port doesn't forward controller-generated packets

Tomasz Osiński osinstom at gmail.com
Sat Dec 19 11:44:07 UTC 2015


Hi,

I've created test network. I have 6 'switch VMs' with OVS instance on every
of them. Every OVS instance is connected to controller-VM. My controller
application generates ARP replies and send PACKET_OUT to requester. My
problem is that ARP reply isn't  forwarded through OVS port.

I've made tcpdump on all involved interfaces. Host(another VM) is trying to
ping IP address 10.0.99.99. Request enters OVS port, then is sent to
controller. Controller sends back ARP reply as i can see it:

tcpdump: listening on eth3, link-type EN10MB (Ethernet), capture size 65535
bytes
12:22:06.637096 52:54:00:d4:2e:de (oui Unknown) > Broadcast, ethertype ARP
(0x0806), length 60: Ethernet (len 6), IPv4 (len 4), Request who-has
10.0.99.99 tell 10.0.1.1, length 46
12:22:06.642559 99:99:99:99:99:99 (oui Unknown) > 52:54:00:d4:2e:de (oui
Unknown), ethertype ARP (0x0806), length 42: Ethernet (len 6), IPv4 (len
4), Reply 10.0.99.99 is-at 99:99:99:99:99:99 (oui Unknown), length 28
12:22:07.654943 52:54:00:d4:2e:de (oui Unknown) > Broadcast, ethertype ARP
(0x0806), length 60: Ethernet (len 6), IPv4 (len 4), Request who-has
10.0.99.99 tell 10.0.1.1, length 46
12:22:07.660575 99:99:99:99:99:99 (oui Unknown) > 52:54:00:d4:2e:de (oui
Unknown), ethertype ARP (0x0806), length 42: Ethernet (len 6), IPv4 (len
4), Reply 10.0.99.99 is-at 99:99:99:99:99:99 (oui Unknown), length 28
12:22:08.653193 52:54:00:d4:2e:de (oui Unknown) > Broadcast, ethertype ARP
(0x0806), length 60: Ethernet (len 6), IPv4 (len 4), Request who-has
10.0.99.99 tell 10.0.1.1, length 46
12:22:08.656520 99:99:99:99:99:99 (oui Unknown) > 52:54:00:d4:2e:de (oui
Unknown), ethertype ARP (0x0806), length 42: Ethernet (len 6), IPv4 (len
4), Reply 10.0.99.99 is-at 99:99:99:99:99:99 (oui Unknown), length 28

Now the problem is that replies are not forwarded back to host(client VM).
Packets stop on this interface. My question is, what is wrong? I've made
tcpdump on bridge that connects two VMs and there tcpdump is as follows:

11:55:04.437453 52:54:00:d4:2e:de (oui Unknown) > Broadcast, ethertype ARP
(0x0806), length 42: Ethernet (len 6), IPv4 (len 4), Request who-has
10.0.99.99 tell 10.0.1.1, length 28
11:55:05.437482 52:54:00:d4:2e:de (oui Unknown) > Broadcast, ethertype ARP
(0x0806), length 42: Ethernet (len 6), IPv4 (len 4), Request who-has
10.0.99.99 tell 10.0.1.1, length 28
11:55:06.455115 52:54:00:d4:2e:de (oui Unknown) > Broadcast, ethertype ARP
(0x0806), length 42: Ethernet (len 6), IPv4 (len 4), Request who-has
10.0.99.99 tell 10.0.1.1, length 28
11:55:07.453478 52:54:00:d4:2e:de (oui Unknown) > Broadcast, ethertype ARP
(0x0806), length 42: Ethernet (len 6), IPv4 (len 4), Request who-has
10.0.99.99 tell 10.0.1.1, length 28
11:55:08.453436 52:54:00:d4:2e:de (oui Unknown) > Broadcast, ethertype ARP
(0x0806), length 42: Ethernet (len 6), IPv4 (len 4), Request who-has
10.0.99.99 tell 10.0.1.1, length 28

So only ARP requests are going through bridge on hypervisor's host. Why ARP
replies are not forwarded to this bridge and then to client's VM ?

Regards,
Tomek
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://openvswitch.org/pipermail/ovs-discuss/attachments/20151219/a490e654/attachment-0002.html>


More information about the discuss mailing list