Brussels / 4 & 5 February 2023


Dear admin, where’s my network?

Overview of (un)reliable methods for vNIC to network mapping with KubeVirt

With a VM attached to multiple networks, it may become difficult and sometimes impossible for its workload to recognize which interface is connected to which network. In this presentation, we will cover various vNIC to network mapping options, their advantages and limitations.

The traditional interface naming scheme (eth0, eth1) does not play well when multiple network devices are present in a system. The names are dependent on the device detection order, which makes them unreliable over reboots.

Modern OS have started using predictable naming schemes for some time now, making the traditional naming scheme a thing of the past.

KubeVirt [1] provides several options that allow to reliably map vNICs to networks in guests: - Based on MAC address. - Based on the PCI address. - Based on the ACPI index. - Based on the device-role-tagging [2].

While we will use KubeVirt as an example, note that these methods are applicable to other platforms too.

Prior familiarity with virtualization and basics of networking are recommended. The audience will walk out knowing how to use the various network mapping methods and understand their pros and cons.

[1] [2]


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