ZS works perfectly in a physical and logical topology with the catalyst 2960 , I’m using almost the same ,and I haven’t any problems about VLANs and trunking . But is needed more info about your config. , eg. ip addresses , firewall rules , nat , default gateway …How you connect to the internet ? 3g modem ? an access port of your catalyst is member of VLAN1 and is connected to a modem/router ? ZS acts as default gateway only for hosts on VLAN 2 or hosts on both VLANs 1/2 ?