Gluster users - Oct 2017 - how does gluster decide which connection to use?

hi everyone

I assume such a situation where network segement changes, in 
a simplest case where one provides a box(a brick) a new 
faster net iterface. So after boxes have two nics and then 
bricks gets introduced to them via gluster probe $_newIPs.

Ideally @ a developer - how gluster handles such a 
situation? Will it deterministically decide which connection 
to use?

Would there be a doc/howto on switching/migrating NICs(not 
by a replacement but by an expansion). I sroogled but failed 
to find one.

many thanks, L.