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[Chu Duc Minh <chu.ducminh@xxxxxxxxx>]

I switched from GRE to VLAN, because my Openstack-cluster needs to operate
with multi- old server farms.
(these multi- old server farms connected using VLAN over Layer3 switch)

With GRE, i have not figured out a way to connect to old server farm, then
I must switch to VLAN.
Another point, VLAN give my network topoloy more clear & reduce overhead of
management (when add a tenant) - in my scenario.

But I strongly believe that, whatever I can do using VLAN, i can do with
GRE. I just don't have enough time to master OpenvSwitch/OpenFlow.

IMHO, GRE could increase workload on network node & compute nodes, because
it needs to do more work (but not much) to tunnel/detunnel the traffic in
VM network(s).

If I'm wrong, could you correct for me?

Thank you, folks!


On Sat, Jun 8, 2013 at 4:33 AM, Kannan, Hari <hari.kannan@xxxxxx> wrote:

>  Slightly off topic question – as I’m fairly new to O~S ****
>
> ** **
>
> What is the use case scenario for preference towards GRE vs VLAN? I would
> have thought GRE is “more” preferable as it doesn’t require external h/w
> configuration as well as doesn’t come with the VLAN scalability limitations
> etc.. ****
>
> ** **
>
> What is a “preferred” deployment model? Why would I choose one over the
> other??
>
> Hari****
>
> ** **
>
> *From:* Openstack [mailto:openstack-bounces+hari.kannan=
> hp.com@xxxxxxxxxxxxxxxxxxx] *On Behalf Of *Aaron Rosen
> *Sent:* Wednesday, June 05, 2013 3:26 AM
> *To:* Chu Duc Minh
> *Cc:* openstack@xxxxxxxxxxxxxxxxxxx
> *Subject:* Re: [Openstack] Quantum VLAN tag mismatch between Network-node
> and Compute-node****
>
> ** **
>
> Hi, ****
>
> ** **
>
> Those vlan tags you are showing are not the actual tags that will be seen
> on the wire. Those tags are auto incremented and used for each new port
> that lands on a server that is in a different network. If you run ovs-ofctl
> dump-flows br-int you'll see those vlan tags are stripped off and the
> correct one is added. ****
>
> ** **
>
> ** **
>
> Look here
> https://github.com/openstack/quantum/blob/master/quantum/plugins/openvswitch/agent/ovs_quantum_agent.py#L326 if
> your curious about what's going on.****
>
> ** **
>
> Aaron****
>
> ** **
>
> On Wed, Jun 5, 2013 at 2:25 AM, Chu Duc Minh <chu.ducminh@xxxxxxxxx>
> wrote:****
>
> Hi, i'm converting from GRE tunnel to VLAN tagging, and deleted all old
> project/user/net/subnet. ****
>
> ** **
>
> in file /etc/quantum/plugins/openvswitch/ovs_quantum_plugin.ini @ all
> nodes, I already set:****
>
> network_vlan_ranges = physnet1:2:4094****
>
> When I create a new net: ****
>
> +---------------------------+--------------------------------------+****
>
> | Field                     | Value                                |****
>
> +---------------------------+--------------------------------------+****
>
> | admin_state_up            | True                                 |****
>
> | id                        | 6d7b116e-be0b-4019-8769-a50a9ca13406 |****
>
> | name                      | net_proj_one                         |****
>
> | provider:network_type     | vlan                                 |****
>
> | provider:physical_network | physnet1                             |****
>
> *| provider:segmentation_id  | 2  *                                  |****
>
> | router:external           | False                                |****
>
> | shared                    | False                                |****
>
> | status                    | ACTIVE                               |****
>
> | subnets                   | 959fe9e0-a79d-4d0f-8040-ebfab26d8182 |****
>
> | tenant_id                 | 29ba82e97f374492a4ca02c62eb0a953     |****
>
> +---------------------------+--------------------------------------+****
>
> ** **
>
> But when i show in network-node:****
>
> # ovs-vsctl show****
>
> ...****
>
> Bridge br-int****
>
>         Port "tapdddef664-ee"****
>
> *            tag: 1*****
>
>             Interface "tapdddef664-ee"****
>
>                 type: internal****
>
>         Port "qr-f9ba0308-2c"****
>
> *            tag: 1*****
>
>             Interface "qr-f9ba0308-2c"****
>
>                 type: internal****
>
>         Port "int-br-eth0"****
>
>             Interface "int-br-eth0"****
>
>         Port br-int****
>
>             Interface br-int****
>
>                 type: internal****
>
>     Bridge "br-eth0"****
>
>         Port "br-eth0"****
>
>             Interface "br-eth0"****
>
>                 type: internal****
>
>         Port "phy-br-eth0"****
>
>             Interface "phy-br-eth0"****
>
>         Port "eth0"****
>
>             Interface "eth0"****
>
> ** **
>
> interface for router & dhcp created are created in VLAN 1 (wrong! it
> should be created with VLAN 2)****
>
> I try to find in config and database, but i can't found which setting that
> start with VLAN 1.****
>
> ** **
>
> Because of VLAN tag mismatch, I can't access to VM instance.****
>
> Another weird thing is on compute node, tag is not constant when i
> create/terminate new instance:****
>
> # ovs-vsctl show ****
>
> a9900940-f882-42f8-9b7c-9b42393ed8a4****
>
>     Bridge "qbred613362-fe"****
>
>         Port "qvbed613362-fe"****
>
>             Interface "qvbed613362-fe"****
>
>         Port "qbred613362-fe"****
>
>             Interface "qbred613362-fe"****
>
>                 type: internal****
>
>         Port "taped613362-fe"****
>
>             Interface "taped613362-fe"****
>
>     Bridge "br-eth1"****
>
>         Port "eth1"****
>
>             Interface "eth1"****
>
>         Port "br-eth1"****
>
>             Interface "br-eth1"****
>
>                 type: internal****
>
>         Port "phy-br-eth1"****
>
>             Interface "phy-br-eth1"****
>
>     Bridge br-int****
>
>         Port br-int****
>
>             Interface br-int****
>
>                 type: internal****
>
>         Port "qvo9816466e-22"****
>
> *            tag: 5*****
>
>             Interface "qvo9816466e-22"****
>
>         Port "int-br-eth1"****
>
>             Interface "int-br-eth1"****
>
>         Port "qvoed613362-fe"****
>
> *            tag: 5*****
>
>             Interface "qvoed613362-fe"****
>
>     Bridge "qbr9816466e-22"****
>
>         Port "qbr9816466e-22"****
>
>             Interface "qbr9816466e-22"****
>
>                 type: internal****
>
>         Port "tap9816466e-22"****
>
>             Interface "tap9816466e-22"****
>
>         Port "qvb9816466e-22"****
>
>             Interface "qvb9816466e-22"****
>
>     Bridge "virbr0"****
>
>         Port "virbr0"****
>
>             Interface "virbr0"****
>
>                 type: internal****
>
> ** **
>
> Do you know why it happen?****
>
> ** **
>
> When everything is ok, *tag* on both Network-node & Compute-node should
> equal *2 *(for first VM network) when I configured "*network_vlan_ranges
> = physnet1:2:4094*" ??****
>
> ** **
>
> Thank you very much!****
>
>
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>
> ** **
>