[j-nsp] EX switches - jumbo frames - vlan interface - interface range - virtual chassis

[pkc_mls]

Hi all,

I'd like to test jumbo frames on a set of ex4200 running as virtual 
chassis.

I configured several ports in an interface range
[edit interfaces interface-range RANGE1]
member-range ge-0/0/0 to ge-10/0/0;
mtu 9216;
ether-options {
        flow-control;
}
unit 0 {
          family ethernet-switching {
                     vlan {
                         members storage;
                     }
            }
}

storage vlan is configured as below :
[edit vlans]
storage {
     vlan-id 10;
     l3-interface vlan.10;
}

vlan interface is :
[edit interfaces vlan]
unit 10 {
     family inet {
         address 10.10.10.1/24;
     }
}

jumbo frames are switched correctly inside vlan 10, but if I try to ping 
from the ex with a size bigger than 1491, it fails.

I tried to set mtu on vlan interface and on vlan unit, without success.

Can anyone indicate how to be able to send/receive jumbo frames on vlan 
interface?

Thanks.