While configuring sub-interface on 7600 a weird issue was observed. It was not allowing us to create vlan 1010 and throws a “errors % Configuring IP routing on a LAN subinterface is only allowed if that subinterface is already configured as part of an IEEE 802.10, IEEE 802.1Q,or ISL vLAN. To solve this issue we need to run the command “show vlan internal usuage” which tells about the status of vlan used by the module.