Hi
We've got our 7210s connected to Cisco 3172 10Gb switches with no issues. We used the Aruba SFP+, normal short fibre patches, and connected to the 40Gb/10Gb "spider" breakout cables on the Cisco side. The only issue we had was a bad patch cable that caused the Cisco port to go down all the time, until it locked up in the down state and we had to reboot the switch to get the port back (apparently a "known issue" on the switches). When we replaced the patch cable, it was all fine.