Every few years I get the idea of migrating various management interfaces on different network devices to a single stacked IPv6 configuration. Most recently this has been Juniper EX series vme interfaces. I wanted to write about what appears to be a Junos bug, for which I haven’t been able to locate a Juniper PR.

What’s the VME interface?

VME stands for “virtual management ethernet”. It’s present on Juniper EX and QFX switches, since those are the models that support Juniper’s virtual chassis. This interface takes the physical me0 (management ethernet) interface, and virtualizes the configuration across the entire virtual chassis.

I’ve spent the past several years managing a fleet of several hundred Juniper QFX10000 switches. These have primarily been the QFX10002 fixed switches, but there’s been a few chassis switches in there too. As more and more of these were deployed, I started to notice an increasing number of hardware failures, specifically with the HMC. (HMC stands for “hybrid memory cubes”, which is the memory used by the forwarding plane.)