Just a quick note, in your first post you say "talk out of two different interfaces" and then talk about the physical interface properties.  Physical interface properties are actually devices, and then you'd build interfaces on top of that.  So your 4 x 1Gb would be some kind of portchanneled/FSN device, and your 2 x 10Gb would be another portchanneled/FSN device.  Then with this physical separation you would create an interface on each, assign an IP address, and then assign both interfaces to the CIFS server in the CIFS server properties.   If you are connecting interfaces directly to the backup server (point to point) then you can use some kind of small private addressing like 192.168.50.0/28 or /29.  You can do the same thing via switching but need to check on VLAN, etc.  I agree with the rest of the posters that you want to use different subnets for each interface.  This is a historically known problem of trying to get a server to talk out of two interfaces on the same subnet with consistent behavior - not limited to VNX.
Hi there,   Can you connect a VNX CIFS server to two different interfaces? These would be the 4 x 1GbE standard ports plus 2 x 10GbE (LC), the idea being that we can use the 10GbE ports to backup from.   Thanks,   Ed
VNX CIFS two different speed interfaces