>Each of the two physical network connections will connect >to a different top of rack router. > >Sure, you can do it with something like MLAG, but that's >really just moving your SPOF to somewhere else (the router >software running MLAG). Router software being super buggy, >I wouldn't rely on MLAG being up at all times.

I would strongly consider doing this via pure L3 routing. This is a scale at which the benefits of L2 fabric switching vs L3 multihomed routing (yes, routing decisions on every node) begin to be interesting decisions.