Cisco doc (http://www.cisco.com/en/US/prod/collateral/switches/ps9441/ps9670/white_paper_c11-560403.html) about FIP advises the following:
"The FIP VLAN discovery protocol is the only FIP protocol running on the native VLAN; all other FIP protocols run on the discovered FCoE VLANs."
As for FCoE in UCS, Is the native vlan mentioned above FCoE native VLAN (by default is vlan 4049 in UCS 2.0) ?