dhcp, cisco layer 3 and brocade icx6450 functionality

I am learning to program our brocade switches and I am struggling with a few things.We use a cisco layer 3 for our core switch.  I create all new vlans on the cisco. If I plug my laptop directly into the cisco and change the port to “access” and assign my new vlan to the port, I get an ip address as expected. However, I created the new vlan on the brocade and tagged the port but it doesn’t seem to obtain an ip address from the dhcp server.  I am thinking it’s a trunk port to trunk port issue.  How do I make the brocade uplink to the cisco a trunk port?  Any other suggestions?  Thank you.