If you are using Verizon Wireless modem, try following.
Setup network for VM host only, in System Preferences Network- Share internet connection from Verizon modem to Parallels Host-Guest adapter.
Please not some models just shutdown Parallels interfaces.
if it is still not work, please perform in Terminal following command
ifconfig -a
sudo killall -HUP pvsnatd
last command can help, of driver from Verizon not one which shutdown interface