Looking at the FAS32XX Installation and Setup instructions
( http://now.netapp.com/NOW/knowledge/docs/hardware/filer/210-04848+A0.pdf )
It seems that c0a and c0b are for cluster interconnect. I only see e0a and e0b (1g ether) for NAS traffic.
It also says that c0a and c0b could be copper or fiber. I'd guess that you do stretch MC with fibre connects,
I'd guess that with fibre for interconnect you could do stretch MC, but it's just a guess...
I hope this response has been helpful to you.
At your service,
Eugene E. Kashpureff
ekashp@kashpureff.org
Fastlane NetApp Instructor and Independent Consultant
http://www.fastlaneus.com/ http://www.linkedin.com/in/eugenekashpureff
(P.S. I appreciate points for helpful or correct answers.)