Hello Evgenly,
Hopefully, you figured out the answer by this time.
Only active-backup ( mode 1 ) is supported on servers managed by UCSM / FI
https://www.kernel.org/doc/Documentation/networking/bonding.txt
For baremetal OS, it is recommended to use Fabric Failover feature in UCSM ( UCS handles NIC redundancy ).
It also eliminates configuration requirement from OS as only one NIC interface is visible to it.
Thanks
Padma