QFX5100 not getting a dhcp address on the mgmt interface

Hi all

I have a QFX5100 that I am configuring. I connected the ethernet mgmt port to my dhcp server and set the em0 unit 0 to receive dhcp. but still it is not getting an dhcp address. What's going on?

Thanks

Here are my config for the mgmt interface: 

em0 {
    unit 0 {
         family inet {
               dhcp{
                        vendor-id Juniper-qfx5100-48s-6q;
               }
         }
    }
}

em1 {
       unit 0 {
              family inet {
                          dhcp {
                                  vendor-id Juniper-qfx5100-48s-6q;
                           }
               }
        }
}

Thanks