Arris S34 Second Ethernet WAN Port

Hello all - just purchased an Arris S34 and wondered if Cox ever started allowing simultaneous use of both ethernet WAN ports on the back of the modem.  I'd like to keep my "old" network connected to the 1gb WAN while I hook up and setup my "new" router and network on the 2.5gb WAN port.  Is this possible or does Cox still only allow one or the other?  TIA!