No Virtual SRX Clusters on VMWare Fusion?

Recently I was working with a customer and looking to test some SRX Cluster configurations that I had written for them before our lab gear became available. No problem I figured, I can easily mock this up with Firefly Perimeter (aka vSRX) on my laptop. However when I tried I couldn’t get the links between the members to come up and the boxes never clustered.

Well, there’s more than one way to skin a cat I thought, I’ve got some Junosphere time that I could use to check everything. Wrong again, I had the same problem.

Poking around I found an article (near the top of page 9) which said that SRX clusters weren’t supported on Junosphere, but didn’t say why. I never did find an article which said that it won’t work in VMWare Fusion on my Mac, in fact in this document it tells how to set it up in vSphere. But when reviewing the technical requirements of those links – which, if you’ll recall, Juniper says should be direct cable connections rather than passing through a switch if possible – I found that the Control Plane connections have to have an MTU of 9014 bytes (1632 on the SRX100s). Now when I go back to the previous document, I find the key line on page 31:

"Click on Properties to turn on the following features:
• General-> Advanced Properties:
• MTU: 9000"

There's only one more piece of the puzzle to find now, and that would be a document saying that you can't set the MTU above 1500 on Fusion interfaces, but I can't find one. And I'm not the only one. While my searches turned up nothing saying it's not supported or telling me how to do it, I found a number of forum questions asking why jumbo frames weren't working. So in the end, it appears that Fusion doesn't support jumbo frames so it isn't able to support vSRX clustering.