[ovs-discuss] ovs-docker: why need to use veth pair instead of internal port?

[Gurucharan Shetty]

On Mon, Apr 27, 2015 at 11:19 PM, Han Zhou <zhouhan at gmail.com> wrote:
> Hi Shan,
>
> Thanks, but why can't we just add an internal port to OVS bridge and
> put into namespace?
> And what's the native support mentioned in INSTALL.docker.md?
You can do it, and its performance is a lot better. But
1. once a OVS internal port has been moved inside a namespace, the
ovs-vswitchd daemon running in the root namespace can no longer see it
and starts complaining.
2. If you are depending on network counters to figure out how much
packets have gone through etc, it gets confusing.
3. When you upgrade your kernel module, the internal interfaces will
disappear from inside the container, likely causing unexpected
behavior for the applications running inside and you will also need a
mechanism to move them all back in after the interface are re-created.

So to take the easier path, ovs-docker utility does not use OVS
internal interfaces but rather uses veth pairs.


>
> Best regards,
> Han
>
> On Tue, Apr 28, 2015 at 2:13 PM, Shanmugam Sundaram
> <shanmugam.s at bizruntime.com> wrote:
>> Hi Han,
>>
>> Dockers uses NameSpaces for isolation, to connect between network
>> namespaces, we have to go with veth pairs.
>>
>> regards,
>> Shan
>>
>> On Tue, Apr 28, 2015 at 11:35 AM, Han Zhou <zhouhan at gmail.com> wrote:
>>>
>>> Hello everyone,
>>>
>>> I have a question about the ovs-docker utility. Why can't internal
>>> port work for docker case? For native support, does it mean we need a
>>> new port type?
>>>
>>> Best regards,
>>> Han
>>> _______________________________________________
>>> discuss mailing list
>>> discuss at openvswitch.org
>>> http://openvswitch.org/mailman/listinfo/discuss
>>
>>
>>
>>
>> --
>> regards,
>> Shan
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