[ovs-discuss] communication between two ovs bridges

[Scott Lowe]

Please see my reply inline, prefixed by [SL].


On 03/09/2017 03:12 AM, David Gabriel wrote:
> Thanks for your reply.
> What do you suggest to ensure the communication between the VMs using my
> topology.
> It is possible to create it based on openstack.
> Any help is welcome.


[SL] Based on the information provided, I'm guessing that you want to
run OVS inside a guest VM that is running on an OpenStack-managed
hypervisor. If that is the case, then a lot will depend on how your
OpenStack installation is configured:

- If you are using OpenStack Neutron with another SDN solution
underneath, that solution may not support NICs running in promiscuous
mode, which I believe would be required in order to run OVS in a VM on
top of OpenStack.

- If you are using OpenStack Neutron with VLAN-backed networks, then you
may be fine running OVS in a guest VM.

If your primary interest is simply using patch ports to connect 2 OVS
bridges, then I'd suggest running them in a single VM.

I'm afraid we'll need more information in order to be able to help you.


> Thanks in advance.
> Best regards
> 
> 2017-03-08 20:54 GMT+01:00 Scott Lowe <scott.lowe at scottlowe.org
> <mailto:scott.lowe at scottlowe.org>>:
> 
> On 03/08/2017 10:12 AM, David Gabriel wrote:
>> Dears,
>>
>> I have defined two ovs bridges, each one of them is deployed in one
>> Virtual Machine (VM) based on this simple topology:
>>                     Internet ----- OVS1 ----LAN---- OVS2 -----Internet
>> I used the following commands for OVS1:
>> ovs-vsctl add-br mybridge1
>> ifconfig mybridge1 up
>> ovs-vsctl add-port eth1 mybridge1 //eth0 is dedicated for Internet
>> ifconfig eth1 0
>> ovs-vsctl add-port eth1 mybridge1
>> ovs-vsctl set-controller mybridge tcp:AddressOfController:6633
>>
>> Then I added a patch port for each bridge based on this tutorial
>>
>> <http://blog.scottlowe.org/2012/11/27/connecting-ovs-bridges-with-patch-ports/
>> <http://blog.scottlowe.org/2012/11/27/connecting-ovs-bridges-with-patch-ports/>>
>> ovs-vsctl add-port mybridge1 patch2-1
>> ovs-vsctl set interface patch2-1 type=patch
>> ovs-vsctl set interface patch2-1 options:peer=patch2-1
>>
>> Then I tried to make the ping between the two VMs but it fails !
>> Could you please tell me how to fix this problem.
> 
> 
> It's my understanding that patch ports should only be used to connect
> OVS bridges running on the same system. Since your bridges are across
> two different VMs, using a patch port here won't work.


-- 
Scott