[ovs-discuss] Troubleshooting network issues with ovn without network namespaces

Daniel Alvarez Sanchez dalvarez at redhat.com
Tue Sep 19 08:16:46 UTC 2017


Hi Vikrant,

Please note that you won't see the metadata namespace getting created
right after creating a network. The namespace will be present only when
necessary; ie., when a port is bound to a chassis and then the metadata
agent
will detect that condition and create/provision the metadata namespace
accordingly *in that chassis*.

So for you to be able to use this namespace for debugging, you would need
a VM running on that node (or bind a port manually to it through the
iface-id
external_id).

Cheers,
Daniel



On Tue, Sep 19, 2017 at 10:06 AM, Numan Siddique <nusiddiq at redhat.com>
wrote:

>
> Hi Vikrant,
>
> Please see this link - https://gist.github.com/russ
> ellb/4ab0a9641f12f8ac66fdd6822ee7789e  and grep for "add_phys_port".
>
> Can you see what is the value of "ovn_metadata_enabled" in the file
>  /etc/neutron/plugins/ml2/ml2_conf.ini.
> If it is false, then please change it to true and restart the
> neutron-server. When you create a new network, you should see a metadata
> namespace getting created.
>
>
> Thanks
> Numan
>
>
> On Tue, Sep 19, 2017 at 9:32 AM, Vikrant Aggarwal <ervikrant06 at gmail.com>
> wrote:
>
>> Thanks for your reply Russell.
>>
>> I installed devstack with latest development releases but I don't see the
>> namespace created with latest version also.
>>
>> ~~~
>>
>> [stack at devstack-centos-controller devstack]$ grep -i ovn local.conf  |
>> grep -v "#"
>> enable_plugin networking-ovn https://git.openstack.org/open
>> stack/networking-ovn
>> enable_service ovn-northd
>> enable_service ovn-controller
>> enable_service networking-ovn-metadata-agent
>>
>> [stack at devstack-centos-controller devstack]$ neutron net-list
>> neutron CLI is deprecated and will be removed in the future. Use
>> openstack CLI instead.
>> +--------------------------------------+-----------+--------
>> --------------------------------------------------+
>> | id                                   | name      |
>> subnets                                                  |
>> +--------------------------------------+-----------+--------
>> --------------------------------------------------+
>> | 786530e0-775b-482c-8149-c6e751c188da | internal1 |
>> dc4961f7-0be3-46be-a545-da7e3a9add8c 10.10.10.0/24       |
>> | 823cab04-68ea-4d02-843d-ab420e2b0709 | private   |
>> 00893897-44b3-42e6-9b2d-568568fae221 fde5:d829:f076::/64 |
>> |                                      |           |
>> 10b1f798-729c-4329-ae0a-65946fee80e4 10.0.0.0/26         |
>> | e1ddda3d-eab5-46a9-a880-15f4eab0360c | public    |
>> b785fc74-ee29-4d0d-bd1f-234337528024                     |
>> |                                      |           |
>> d49dc742-9709-4e3b-8a45-68333b7af8b1                     |
>> +--------------------------------------+-----------+--------
>> --------------------------------------------------+
>>
>> [stack at devstack-centos-controller devstack]$ ip netns list
>> [stack at devstack-centos-controller devstack]$
>> ~~~
>>
>> Can you please share the steps if you have them handy.
>>
>> Thanks & Regards,
>> Vikrant Aggarwal
>>
>>
>> On Tue, Sep 19, 2017 at 1:51 AM, Russell Bryant <russell at ovn.org> wrote:
>>
>>> On Fri, Sep 15, 2017 at 12:45 AM, Vikrant Aggarwal
>>> <ervikrant06 at gmail.com> wrote:
>>> > Hi Folks,
>>> >
>>> > With ovs as mechanism driver in neutron, I used network namespaces
>>> often to
>>> > troubleshoot the network related issue especially with instances which
>>> are
>>> > not having floating ip attached to them. It's easy to take ssh session
>>> to
>>> > instances without floating ip from network namespace and then take the
>>> > tcpdump at various hops to troubleshoot the issue.
>>> >
>>> > With ovn, hops are reduced as all decisions are made using openflows
>>> but
>>> > it's difficult to troubleshoot the issue.
>>> >
>>> > Do we have any mechanism to take the ssh session to instance with only
>>> > private ip in case of ovn and take tcpdump on logical switches and
>>> ports?
>>>
>>> If you're using the latest Neutron integration (networking-ovn), we
>>> now create namespaces for OpenStack metadata API integration.  You can
>>> use those namespaces like you did before.
>>>
>>> The other option would be to manually create a Neutron port, and then
>>> manually create an interface in a namespace for that Neutron port.  I
>>> can send instructions if needed ...
>>>
>>> --
>>> Russell Bryant
>>>
>>
>>
>> _______________________________________________
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>> discuss at openvswitch.org
>> https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
>>
>>
>
>
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