Symptom:
FC traffic stops working on fabric interconnect only on certain chassis after firmware upgrade.  However, blades in those chassis have successfully flogi into the fabric.

On the upstream fabric switch fc4 feature types are missing when checking "show fcns database detail" for the affected blades.

------------------------
VSAN:20    FCID:0x640f58
------------------------
port-wwn (vendor)           :20:00:00:25:b5:0a:00:7d             
node-wwn                    :20:00:00:25:b5:01:00:1c
class                       :3
node-ip-addr                :0.0.0.0
ipa                         :ff ff ff ff ff ff ff ff
fc4-types:fc4_features      :
symbolic-port-name          :
symbolic-node-name          :
port-type                   :N 
port-ip-addr                :0.0.0.0
fabric-port-wwn             :24:1e:54:7f:ee:d8:db:00
hard-addr                   :0x000000
permanent-port-wwn (vendor) :24:1e:00:0d:ec:db:d8:40 (Cisco)     
connected interface         :port-channel 30
switch name (IP address)    : 10.10.10.10

Running show platform fwm info pif ethernet X/X on the connections to the IO module to the affected chassis show pif drops for FCoE traffic:

Eth1/9 pd fcoe: tx stats: bytes 162307365992 frames 122531798 discard 0 drop 0 
Eth1/9 pd fcoe: rx stats: bytes 429679500900 frames 226619896 discard 0 drop 487 

Eth1/10 pd fcoe: tx stats: bytes 95123227788 frames 75500132 discard 0 drop 0 
Eth1/10 pd fcoe: rx stats: bytes 100326062120 frames 63567768 discard 0 drop 209

Conditions:
Occurs after firmware upgrade