Connectivity for a C240 M3 with two 10 GB PCI cards to Fabric Inteconnect

[Bob Fry]

I understand if there is one 10 GB PCI card from a C240 M3 going to the Fabric Interconnects you would need to cross the connections one going to FAB-A and one going to FAB-B.  However, if you have two PCI cards do you plug all of adapter 1 into FAB-A and plug all of adapter 2 into FAB-B or do you still split them out?

[Manuel Velasco]

Hi Bob,

I am assuming you are talking about c-series integration with ucsm using a c240 with dual VIC adapters ( VIC 1225).  If this is the case you want to have both adapter connected to each UCS fabric interconnect for redundancy purposes.  The reason for this is, if one of your fabrics goes down, all of the vnics mapped with the adapter connected to a single fabric will lose connectivity to the outside network even though you have configured the failover option at the vnic level.  They would go down as there would be no path to connect to the other fabric.

Please let me know if this helps.

[Walter Dey]

see also

http://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/c-series_integration/ucsm2-2/b_C-Series-Integration_UCSM2-2.pdf --> Fig 13

By dual homing each I/O adaptor, you avoid any single point of failure (at least from the connectivity point of view