If you are configuring vlan trunking on your switch and the related subinterfaces on your router, must you have routing turned on before you configure the router? We are doing some prep work on our routers and encountering some odd behavior when configuring the subinterfaces. The worst of which is that we loose connectivity to the router when we turn on the encapsulation on the subinterface. BTW> We haven't turned on routing yet because decisions are still being made regarding AS numbers and redistributions, so we don't want to negatively impact the production network. Although these new routers are not in production, they are live on the production network.