Bug 2019938 - router ports gateway_mtu option should not always be set
Summary: router ports gateway_mtu option should not always be set
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat OpenStack
Classification: Red Hat
Component: python-networking-ovn
Version: 16.2 (Train)
Hardware: Unspecified
OS: Unspecified
high
high
Target Milestone: z2
: 16.2 (Train on RHEL 8.4)
Assignee: Elvira
QA Contact: Eduardo Olivares
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2021-11-03 16:41 UTC by Elvira
Modified: 2022-03-23 22:12 UTC (History)
4 users (show)

Fixed In Version: python-networking-ovn-7.4.2-2.20220113214852.a2eba10.el8ost
Doc Type: No Doc Update
Doc Text:
Clone Of:
Environment:
Last Closed: 2022-03-23 22:12:24 UTC
Target Upstream Version:
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
OpenStack gerrit 818443 0 None NEW [OVN] Fix gateway_mtu option should not always be set 2021-11-22 08:46:54 UTC
Red Hat Issue Tracker OSP-10642 0 None None None 2021-11-10 14:10:43 UTC
Red Hat Product Errata RHBA-2022:1001 0 None None None 2022-03-23 22:12:49 UTC

Description Elvira 2021-11-03 16:41:17 UTC
Copied from eolivare's previous description on BZ2018459, which is now only used as Test-only track of the Core OVN. This BZ was separated from there since we agreed that there are 2 separate tasks: 1. Test the Core OVN fix 2. Fix how neutron sets the gateway_mtu.

Description of problem:
This bug is a consequence of the investigation of the core ovn bug BZ2017424
See comments 2 and 3 from that bug.
In comment 3, Numan explains that gateway_mtu should not be set in some cases:
"If a neutron router is connected to a provider network 'A' and private geneve networks.  If the mtu of private networks (1442 in normal cases) is lesser than that of provider network (1500), then there is no need for neutron ml2ovn to set options:gateway_mtu=1500 even if the config option to enable gateway mtu is set."


AFAIU, the original issue from BZ2017424 is going to be fixed in OVS, but the change requested in this bug could also help to fix the issue and, in any case, could have a positive performance impact.


Version-Release number of selected component (if applicable):
RHOS-16.2-RHEL-8-20211013.n.1

How reproducible:
100% (See BZ2017424 description)

Steps to Reproduce:
See BZ2017424 description

Comment 2 Elvira 2021-12-10 14:31:43 UTC
Commit merged automatically in rhos-16.2-trunk-patches. Fixed in python-networking-ovn-7.4.2-2.20211209154612.933c1ba.el8osttrunk

Comment 12 errata-xmlrpc 2022-03-23 22:12:24 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (Release of components for Red Hat OpenStack Platform 16.2.2), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2022:1001


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