Bug 2314343 - Add support for ifcfg LINKSTATUS=down in os-net-config
Summary: Add support for ifcfg LINKSTATUS=down in os-net-config
Keywords:
Status: CLOSED NEXTRELEASE
Alias: None
Product: Red Hat OpenStack
Classification: Red Hat
Component: os-net-config
Version: 17.1 (Wallaby)
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
: ---
Assignee: Dan Sneddon
QA Contact: Eran Kuris
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2024-09-23 22:28 UTC by Dan Sneddon
Modified: 2024-10-01 12:38 UTC (History)
4 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Cause: OVS-DPDK User Bridges that have no IP and are only used for provider networks do not require an active internal interface to the kernel. OVS-DPDK User Bridges should remain in a DOWN state when the bridge is enabled. Consequence: If the OVS User Bridge interface is set to UP the kernel will receive unnecessary broadcast and multicast traffic which it has to drop, which uses extra CPU. Fix: The network template for os-net-config now supports the “ovs_internal: [TRUE|FLASE]” parameter. If set to false “LINKSTATUS=down” will be added to the ifcfg file when using the ifcfg provider, which will keep the internal interface disabled. Result:
Clone Of:
Environment:
Last Closed: 2024-10-01 12:38:06 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Bugzilla 1628227 0 high CLOSED OVS-DPDK bridges should be DOWN 2024-09-23 22:45:22 UTC
Red Hat Issue Tracker OSPRH-9560 0 None None None 2024-09-23 22:28:32 UTC

Description Dan Sneddon 2024-09-23 22:28:32 UTC 
Description of problem:
OVS-DPDK User Bridges may be standalone and do not require an active kernel interface. There is a setting for ifcfg files in network-init-scripts that allows this behavior. Add support in os-net-config for setting LINKSTATUS=down in user bridge ifcfg files when using init-scripts instead of NetworkManager

Version-Release number of selected component (if applicable):
17.1.4

How reproducible:
100%

Steps to Reproduce:
1. Configure an ovs-DPDK user_bridge with no IP address
2. Run os-net-config 
3. Bring up the OVS user bridge

Actual results:

The user bridge is brought up with an active kernel interface, which leads to broadcast and multicast traffic hitting the kernel and using excess CPU

Expected results:

The OVS user bridge should be down and not show as “DOWN” in “ip addr”

Additional info:

A fix was made in init-scripts but this support was not added to os-net-config before as there was not a use case before, but now we have a customer who wishes to use the OVS user bridge without support for tunnel networks and needs this feature for maximum provider network performance.
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