Bug 1887456
| Summary: | It is impossible to attach the default NIC to a bridge with the latest version of OVN Kubernetes | |||
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| Product: | OpenShift Container Platform | Reporter: | Petr Horáček <phoracek> | |
| Component: | Networking | Assignee: | Tim Rozet <trozet> | |
| Networking sub component: | ovn-kubernetes | QA Contact: | Ross Brattain <rbrattai> | |
| Status: | CLOSED ERRATA | Docs Contact: | ||
| Severity: | high | |||
| Priority: | high | CC: | anbhat, bbennett, danken, fpan, mcornea, rbrattai, rgarcia, ross.b.brattain | |
| Version: | 4.6 | |||
| Target Milestone: | --- | |||
| Target Release: | 4.7.0 | |||
| Hardware: | Unspecified | |||
| OS: | Unspecified | |||
| Whiteboard: | ||||
| Fixed In Version: | Doc Type: | Bug Fix | ||
| Doc Text: |
Cause:
OVN-Kubernetes takes the default gateway interface on the host and moves it into an OVS bridge called "br-ex". This bridge is primarily used to share the physical NIC of the host with the host network stack as well as OVN. However, there was no accommodation for anything else attaching and using the br-ex bridge (like CNV).
Consequence:
Attaching another interface to br-ex, such as a veth pair to a linux bridge or some other internal interface would not function correctly. Traffic would not egress/ingress as expected from the br-ex bridge to the newly added interface.
Fix:
OpenFlow programmed by OVN-Kubernetes has been fixed to normally switch traffic that does not belong to OVN or the host.
Result:
Attaching a new interface to br-ex will function the same as it would any normal switch such as a linux bridge.
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Story Points: | --- | |
| Clone Of: | ||||
| : | 1889309 (view as bug list) | Environment: | ||
| Last Closed: | 2021-02-24 15:25:25 UTC | Type: | Bug | |
| 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: | ||||
| Bug Blocks: | 1885605, 1889309, 1893160 | |||
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Description
Petr Horáček
2020-10-12 14:16:21 UTC
Shared gw fix is merged into 4.7. Testing local gateway fix that will be required for 4.6 backport: https://github.com/ovn-org/ovn-kubernetes/pull/1843 Note, the solution to this bug will be to allow other applications on the host to attach a port to br-ex (shared bridge) and traffic will flow normally over it like a regular L2 bridge. OVN-K8S will still take the NIC and move it onto the br-ex bridge at install time. Then CNV or any other application can simply attach to br-ex with an OVS patch port (if connectint to another OVS bridge) or create a veth pair to attach a linux bridge or something else. @rbrattai Can you help looking at this? Verified on 4.7.0-0.nightly-2020-12-03-083300 on OpenStack Created veth pair, attached to Linux bridge, tcpdumped and saw MDNS traffic from all the other nodes in the cluster. ip link add v1 type veth peer v2 ip l s v1 up ip l s v2 up ip link add name br-0 type bridge ip link set br-0 up ip link set v2 master br-0 ovs-vsctl add-port br-ex v1 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 4.7.0 security, bug fix, and enhancement 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-2020:5633 The needinfo request[s] on this closed bug have been removed as they have been unresolved for 500 days |