No kidding.

Just to elaborate for others, MACSec is a standard (802.1ae) and runs at line rate. Something like a Juniper PTX10008 can run it at 400Gbps, and it’s just a feature you turn on for the port you’d be using for the link you want to protect anyway (PTXs are routers/switches, not security devices).

If I need to provide encryption on a DCI, I’m at least somewhat likely to have gear that can just do this with vendor support instead of needing to slap together some Linux based solution.

Unless, I suppose, there’s various layer 2 domains you’re stitching together with multiple L2 hops and you don’t control the ones in the middle. In which case I’d just get a different link where that isn’t true.

I have at least one switch that's MACSec compatible at line speed but I haven't had time to take a look. I guess this is confined to LAN and cannot do a MACSec link through the internet, isn't it?