[c-nsp] Unable to create BFD session on C6500

[Marco Marzetti]

Hello,

We run BFD on all of our devices and we're currently having some 
problems between a pair of C6500/SUP720 and a ME3600X .

The network diagram is as follows:

               +-----------+
               |           |
      +--------+  C6500_1  |
      |        |           |
      |        +----+-+----+
+----+----+        | |
|         |        | |
| ME3600X |        | |
|         |        | |
+----+----+        | |
      |        +----+-+----+
      |        |           |
      +--------+  C6500_2  |
               |           |
               +-----------+

Both the C6500 run the following software: 
s72033-adventerprisek9-mz.151-2.SY2.bin
Both C6500 are SUP720-3B and there isn't any dCEF enabled card on them.

The OSPF sessions on C6500_1 is in FULL state:

C6500_1# show ip ospf neighbor | i 2/7
192.0.2.19    0   FULL/  -        00:00:32    192.0.2.173 GigabitEthernet2/7

and the relevant configuration is as follows:

interface gigabitEthernet 2/7
  ip ospf network point-to-point
  ip ospf 1 area 0
  bfd interval 300 min_rx 300 multiplier 3
  no bfd echo
!
router ospf 1
  bfd all-interfaces
!

Anyway IOS is not able to start a BFD session on that interface:

C6500_1# show ip ospf neighbor 212.183.160.19 | i BFD
C6500_1#

And returns an error when BFD debugging is on:

C6500_1#show debugging
BFD:
   BFD event debugging is on for interface GigabitEthernet2/7
   BFD packet debugging is on for interface GigabitEthernet2/7
C6500_1#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
C6500_1(config)#int gi2/7
C6500_1(config-if)#no bfd interval
C6500_1(config-if)#bfd interval 300 min_rx 300 multi 3
C6500_1(config-if)#
Dec  9 16:07:42.737: BFD-DEBUG EVENT: bfd_session_create failed, 6
C6500_1(config-if)#

At the same time there are running BFD sessions on other interfaces 
configured with the very same statements:

For instance the following interface is connected to another ME3600X 
that is running the same software version:

C6500_1#show bfd neighbors | i 2/6
192.0.2.109                       294/3          Up        Up        Gi2/6
C6500_1#

Can anyone help?

Thank You