Bug 1898567

Summary:	ovs-configuration.service fails when multiple IPv6 default routes are provided via RAs over the same interface and deployment bootstrap fails
Product:	OpenShift Container Platform	Reporter:	OpenShift BugZilla Robot <openshift-bugzilla-robot>
Component:	Networking	Assignee:	Dan Winship <danw>
Networking sub component:	ovn-kubernetes	QA Contact:	Marius Cornea <mcornea>
Status:	CLOSED ERRATA	Docs Contact:
Severity:	urgent
Priority:	urgent	CC:	aconstan, anbhat, mcornea, zzhao
Version:	4.6	Keywords:	TestBlocker
Target Milestone:	---
Target Release:	4.6.z
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-12-14 13:50:58 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1896898
Bug Blocks:

Description OpenShift BugZilla Robot 2020-11-17 14:27:55 UTC

+++ This bug was initially created as a clone of Bug #1896898 +++

Description of problem:
	
ovs-configuration.service when multiple IPv6 default routes are provided via RAs

During deployment on one of the master nodes we get multiple IPv6 default routes over the same interface:

ip -6 r show default
default proto ra metric 101 
	nexthop via fe80::200:5eff:fe00:201 dev eno6 weight 1 
	nexthop via fe80::2e21:3101:b5e3:8f00 dev eno6 weight 1 
	nexthop via fe80::d207:ca01:b521:2700 dev eno6 weight 1 pref medium

Trying to run manually the /usr/local/bin/configure-ovs.sh script we can see that it cannot find the default route as it's assuming only one:

/usr/local/bin/configure-ovs.sh OVNKubernetes
+ rpm -qa
+ grep -q openvswitch
+ touch /var/run/ovs-config-executed
+ '[' OVNKubernetes == OVNKubernetes ']'
+ NM_CONN_PATH=/etc/NetworkManager/system-connections
+ iface=
+ counter=0
+ '[' 0 -lt 12 ']'
++ ip route show default
++ awk '{if ($4 == "dev") print $5; exit}'
+ iface=
+ [[ -n '' ]]
++ ip -6 route show default
++ awk '{if ($4 == "dev") print $5; exit}'
+ iface=
+ [[ -n '' ]]
+ counter=1
+ echo 'No default route found on attempt: 1'
No default route found on attempt: 1
+ sleep 5


Version-Release number of selected component (if applicable):
quay.io/openshift-release-dev/ocp-release:4.6.3-x86_64

How reproducible:
100%

Steps to Reproduce:

1. Deploy baremetal environment via IPI flow with IPv6 control plane. The nodes should receive multiple IPv6 default routes via RAs

Actual results:

ovs-configuration.service assumes a single IPv6 default route

Expected results:

ovs-configuration.service should handle multiple IPv6 default routes over the same interface


Additional info:

Comment 3 Anurag saxena 2020-12-10 15:02:13 UTC

Assigning to @mcornea since he verified the original bug

Comment 4 zhaozhanqi 2020-12-11 03:40:48 UTC

Verified this bug on 4.6.8

Deployed ipv6 cluster and check the ip route

ip -6 r show default
default via fe80::5054:ff:fed9:77d0 dev br-ex proto ra metric 800 pref medium

Comment 6 errata-xmlrpc 2020-12-14 13:50:58 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 (Moderate: OpenShift Container Platform 4.6.8 security and bug fix update), 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/RHSA-2020:5259