can not create l2 gateway connection without specifying segmentation ID

[Sukhdev Kapur]

It is my understanding that the segmentation ID is an optional parameter for the neutron-l2gw l2-gateway-connection-create.

However, if do not specify the segmentation ID, the connection create command fails.

[selvakumar (selvakumar-nms)]

Hi Sukhdev,
your understanding is correct . segmentation_id is optional for both l2-gateway-create & l2-gateway-connection-create commands
But at least one of the command we might need to specify segmentation id. otherwise , L2GatewaySegmentationRequired will be thrown for l2-gateway-connection-create .

could you please post the error what you face in your setup?

[Sukhdev Kapur (sukhdev-8)]

Please see the error message for this failure.

arastra@os-ctrl3:~/devstack$ neutron-l2gw l2-gateway-connection-create gw1 net-1
Invalid input for operation: Segmentation id must be specified in createl2gateway connections.

[selvakumar (selvakumar-nms)]

this is the expected behaviour in the current code and it actually matches our l2gw blueprint.

[Maruti Kamat (marutik)]

Can we modify the error text that the segmentation ID should be either specified while creating the gateway, or while creating the connection?

[selvakumar (selvakumar-nms)]

Hi Sukhdev,
do you agree if I change the error description message for the Exception to resolve this defect?

Agree?

Thanks
Selvakumar

[Sukhdev Kapur (sukhdev-8)]

I believe this is a problematic to say the least.
My understanding has been that we will allow segmentation ID as an optional value for some specific uses. Making it mandatory creates a deployment issues in the Bare Metal Servers. Using segmentation ID implies that BM server will accept tagged packets (which means the port that connects the TOR to BM must be in a trunk mode). Some bare metal servers can not handle tagged packets (and hence require ports to be in the access ports).

If you mandate segmentation ID, you are implying that all BM servers must support tagged frames - this may be an issue with many operators.

Am I misunderstanding the issue? If I am, please correct me. But, if my understanding is correct, this takes away the usability of this feature for some (if not all) deployments.
Something to think about.

-Sukhdev

[selvakumar (selvakumar-nms)]

Sukhdev,

Could you please provide us the ovsdb-client dump without l2 gateway solution if segmentation_id is not configured for the logical switch.
we are interested in vlan_bindings values of Physical_Port in that case .

Thanks

[Sukhdev Kapur (sukhdev-8)]

Hi Selva,
Here is the dump of OVSDB with VLAN=0: Hope this helps.

Arp_Sources_Local table
_uuid locator src_mac
----- ------- -------

Arp_Sources_Remote table
_uuid locator src_mac
----- ------- -------

Global table
_uuid managers switches
------------------------------------ -------- --------------------------------------
445a8b8a-39d5-4e95-8517-86950b0fe2e2 [] [d2c788ae-e112-449b-89f7-e8bb8f2e0377]

Logical_Binding_Stats table
_uuid bytes_from_local bytes_to_local packets_from_local packets_to_local
----- ---------------- -------------- ------------------ ----------------

Logical_Router table
_uuid description name static_routes switch_binding
----- ----------- ---- ------------- --------------

Logical_Switch table
_uuid description name tunnel_key
------------------------------------ ------------------ ------ ----------
1b017376-cd50-44e1-b1fa-c50d826144a1 "a logical switch" "lsw1" 5000

Manager table
_uuid inactivity_probe is_connected max_backoff other_config status target
----- ---------------- ------------ ----------- ------------ ------ ------

Mcast_Macs_Local table
MAC _uuid ipaddr locator_set logical_switch
--- ----- ------ ----------- --------------

Mcast_Macs_Remote table
MAC _uuid ipaddr locator_set logical_switch
--- ----- ------ ----------- --------------

Physical_Locator table
uuid dst_ip encapsulation_type
------------------------------------ ------------- ------------------
402b7d67-4ebc-460e-9856-55702cd7452c "192.168.9.1" "vxlan_over_ipv4"
d207daa2-2f1e-4064-b465-b11d46506306 "192.168.9.2" "vxlan_over_ipv4"

Physical_Locator_Set table
_uuid locators
----- --------

Physical_Port table
_uuid description name port_fault_status vlan_bindings vlan_stats
------------------------------------ ----------- ------ ----------------- ---------------------------------------- ----------
0150d5b7-d92a-4032-b3ca-b359fa74b7e0 "" "eth1" [] {0=1b017376-cd50-44e1-b1fa-c50d826144a1} {}

Physical_Switch table
_uuid description management_ips name ports switch_fault_status tunnel_ips tunnels
------------------------------------ ----------- -------------- ---------- -------------------------------------- ------------------- ---------- -------
d2c788ae-e112-449b-89f7-e8bb8f2e0377 "" [] "pswitch1" [0150d5b7-d92a-4032-b3ca-b359fa74b7e0] [] [] []

Tunnel table
_uuid bfd_config_local bfd_config_remote bfd_params bfd_status local remote
----- ---------------- ----------------- ---------- ---------- ----- ------

Ucast_Macs_Local table
MAC _uuid ipaddr locator logical_switch
--- ----- ------ ------- --------------

Ucast_Macs_Remote table
MAC _uuid ipaddr locator logical_switch
------------------- ------------------------------------ ------------ ------------------------------------ ------------------------------------
"34:34:34:34:34:01" 27102008-e0bd-4...

[selvakumar (selvakumar-nms)]

Posted review to allow segmentation id 0 during connection create.
https://review.openstack.org/#/c/181361/

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/181361
Committed: https://git.openstack.org/cgit/stackforge/networking-l2gw/commit/?id=8d6cb1b3f3f3b5605a881d2b95ac4f3045109c94
Submitter: Jenkins
Branch: master

commit 8d6cb1b3f3f3b5605a881d2b95ac4f3045109c94
Author: Selvakumar S <email address hidden>
Date: Fri May 8 03:54:38 2015 -0700

    Support for specifying segmentation id optional

    This fix for supporting the '0' segmentation id during l2gateway connection create.
    This is applied for the use case where some bare metal server can not handle tagged packets(connected to access ports)

    Closes-Bug:1444188

    Change-Id: Ia92432f0296152116e998ad8418c35ef014f898e