In MQX, there is a shell example where you can try various commands (\Freescale MQX 3.7\rtcs\examples\shell).
You should try that to confirm everything is ok before doing your own app.
With dhcp, you can try commands like:
shell> ipconfig 0 initEthernet device 0 initialization successful.shell> ipconfig dhcpBind via dhcp successful.shell> ipconfig staticip 192.168.1.10 255.255.255.0 192.168.1.1
Static ip bind successful.shell> ping 192.168.1.1
Pinging [192.168.1.1]:Reply from 192.168.1.1: time<1msReply from 192.168.1.1: time<1msReply from 192.168.1.1: time<1msReply from 192.168.1.1: time<1ms
For ethernet apps, remember to configure the system to use clock from TWR-SER otherwise it will not work correctly (if you use clock from TWR-K60, it still may work but fail sometime)
Regards