Yeah, it changes.

    They started with FreeBSD 4.x + their patches, then moved it inside a hardened Linux for virtualization functions (watch closely the boot sequence).

    uname returns

        MX960 - FreeBSD amd64

        QFX 5100 - JUNOS i386 (build tag show indication its FreeBSD still)
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Alain Hebert                                ahebert@pubnix.net   
PubNIX Inc.        
50 boul. St-Charles
P.O. Box 26770     Beaconsfield, Quebec     H9W 6G7
Tel: 514-990-5911  http://www.pubnix.net    Fax: 514-990-9443
On 2020-10-08 18:50, Chris Boyd wrote:

On Oct 8, 2020, at 10:55 AM, <aaron1@gvtc.com> <aaron1@gvtc.com> wrote:

JunOS is so linux based
Um, my MX-204 says FreeBSD amd64.