Bug 1573408

Summary:	[OVN] - Changing the vlan of a physnet does not update the vlan of the external networks defined on top of it
Product:	[oVirt] ovirt-engine	Reporter:	Michael Burman <mburman>
Component:	BLL.Network	Assignee:	Marcin Mirecki <mmirecki>
Status:	CLOSED DEFERRED	QA Contact:	Michael Burman <mburman>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	4.2.3.2	CC:	bugs, danken, dholler
Target Milestone:	---	Flags:	sbonazzo: ovirt-4.3-
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2018-12-12 10:45:11 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	Network	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Michael Burman 2018-05-01 06:21:16 UTC

Description of problem:
Changing the vlan of a physnet does not update the vlan of the external networks defined on top of it. It's a known issue that deserve a clear bug.


Version-Release number of selected component (if applicable):
4.2.3.2-0.1.el7

How reproducible:
100%

Steps to Reproduce:
1) Create new physnet network(data center network) with vlan 162
2) Attach the physnet network to the host 
3) Create new ovn network + choose create on external provider + choose the data center network(physnet network) from step 1^^ without subnet
4) Run VM with ovn network vNIC - VM got IP from vlan 162
5) Shutdown the VM
6) Edit the physnet network with new vlan tag 163 - All changes applied successfully on the host
7) Start VM - 

Result - VM got IP from vlan 162 and not vlan 163

* NOTE - The exact same flow, with regular vlan network(no ovn involved) working as expected.

Actual results:
The physnet vlan wasn't updated

Expected results:
The physnet vlan should be updated

Additional info:
See also BZ 1534565

Comment 1 Dominik Holler 2018-08-02 07:44:08 UTC

An alternative way to fix would be to unlink the oVirt's OVN network entity from the physnet network, instead of update the OVN network's `provider:segmentation_id` as suggested in comment 0.

Comment 2 Dominik Holler 2018-08-02 10:56:49 UTC

Another alternative would be to forbid to change the VLAN ID, if engine knows that the physical network is used as physnet by an external network.

Comment 3 Dan Kenigsberg 2018-12-12 10:45:11 UTC

I prefer the simpler solution proposed in comment 1, but we are unlikely to address it before we hear a demand from the field for physnet, which would occur only after bug 1195208 is out.