Bug 2162345

Summary:	[17.0][ML2-OVS][OFFLOAD][VLAN TRUNK] DHCP taking a long time to get an ip addres for interfaces with vlan trunk configured
Product:	Red Hat OpenStack	Reporter:	Miguel Angel Nieto <mnietoji>
Component:	openstack-neutron	Assignee:	Rodolfo Alonso <ralonsoh>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Eran Kuris <ekuris>
Severity:	high	Docs Contact:
Priority:	unspecified
Version:	17.0 (Wallaby)	CC:	chrisw, hakhande, jraju, mtomaska, scohen
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Last Closed:	2023-04-03 13:13:06 UTC	Type:	Bug
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
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Description Miguel Angel Nieto 2023-01-19 11:36:42 UTC

Description of problem:
This looks like a corner case that is failing under some specific conditions. When configuring several instances with the following interfaces configuration, dhcp takes around 10 minutes to get ip address:

Interfaces:
* net1: vxlan
* net2: vlan
* net3: vlan trunk with parent network net1
* net4: vlan trunk with parent network net2

This issue only happen when there is a odd number of instances in the compute greater than 1.
I tried this combinations:
* 1 instance: OK
* 2 instance: OK
* 3 instance: FAIL
* 4 instance: OK
* 5 instance: FAIL

I also tested other combinations:

* VXLAN and vlan trunk: PASS
  net1: vxlan
  net3: vlan trunk with parent network net1

* VLAN and vlan trunk: PASS
  net2: vlan
  net4: vlan trunk with parent network net2

Version-Release number of selected component (if applicable):
RHOS-17.0-RHEL-9-20221213.n.1


How reproducible:
1. deploy ml2-ovs offload with osp 17.0
2. create 3 instances in one compute with 4 networks as describe before
3. assing a fip to one of the interfaces
4. check ping, it should fail
5. connect though the console and check that interfaces does not have an ip address
6. wait around 10 minutes, interfaces are configured

Actual results:
it take a long time for dhcp to get ip addresses


Expected results:
dhcp should assing ip address faster


Additional info: