on the CCR1009, the first 4 ports can be used for switching, so I suggest using Eth5 and Eth6 for WAN1 and WAN2, and the 1-4 for switching.
To configure ports in switch mode, set one of them as the master for others. For example, open up the Eth2 port in Interfaces → Ethernet, and set Eth1 as master for this port. Then set the same for other ports that you want to be part of the switch. Any port can be master for the others, but they all have to be from the Group1 (Eth1-Eth4)