I figured it out - the switch moved its own uplink when I bounced the MX so it was blackholing the traffic ... View more

MX84 is impacted by a brief reset on certain config changes. It's always been present. This is in all firmware version release notes.     But if you're seeing it go down and never come back without doing a reboot that's a different issue. ... View more

How much separation do you need? And is it really only outbound traffic or also inbound? If it is only outbound, do you really need the old firewall or can you just configure a VLAN with the subnet of the old firewall and replace the old device? For Internet-access, PAT is done automatically when you send  traffic to the MX on a LAN interface. ... View more