How to configure a Layer 3 switch as a router in 3 easy steps.

The order these are performed should not matter.

Setup the interfaces

int f1/0/1
no switchport
ip address 10.10.10.1 255.255.255.0
no shutdown
int f1/0/2
no switchport
ip address 10.10.20.1 255.255.255.0
no shutdown

Enable routing

ip routing

Configure any additional routes or routing protocols as required.