I have a 3640 that's running enterprise plus (c3640-js-mz.124-17.bin). The config is as follows:
ip address 192.168.36.1 255.255.254.0
encapsulation dot1Q 1 native
description VLAN 20- Voice VLAN
encapsulation dot1Q 20
ip address 10.0.36.1 255.255.254.0
Whenever I remove the address from e0/0 and put it on the subinterface with the native VLAN, I lose all connectivity. This router is connecting to a Dell 6248. This switch is a Layer 3 switch. Any suggestions?