SmartFabric mode supports three specific switch placement options. Attempts to use placements different than described here is not supported and may result in unpredictable behavior and/or data loss.
A SmartFabic cannot be split across physical fabric slots. For example, you cannot create a SmartFabric with switches in slot A1 and B1. They must be A1/A2 or B1/B2.
Two MX9116n Fabric Switching Engines in different chassis
This is the required IOM placement when creating a SmartFabric on top of a Scalable Fabric Architecture. Placing the FSE modules in different chassis provides redundancy in the event of a chassis failure. This configuration supports placement in Chassis1 Slot A1 and Chassis 2 Slot A2 and/or Chassis1 Slot B1 and Chassis 2 Slot B2. A SmartFabric cannot include a switch in Fabric A and a switch in Fabric B.
Two MX5108n Ethernet switches in the same chassis
The MX5108n Ethernet Switch is only supported in single chassis configurations, with the switches in either slots A1/A2 or slots B1/B2. A SmartFabric cannot include a switch in Fabric A and a switch in Fabric B.
Two MX9116n Fabric Switching Engines in the same chassis
This placement should only be used in environments with a single chassis, with the switches in either slots A1/A2 or slots B1/B2. A SmartFabric cannot include a switch in Fabric A and a switch in Fabric B.
As of OME-M 1.20.00, an MX deployment can start with a single MX7000 chassis with a pair of MX9116n FSEs and grow to two or more chassis. The instructions for this can be found in this document in Expanding from a single-chassis to dual-chassis configuration.