interface FastEthernet0.20
encapsulation dot1Q 20 no ip route-cache bridge-group 1 no bridge-group 1 source-learning bridge-group 1 spanning-disabled
! Supports shortened versions of config words, too inter gi0.10 encap dot1q 10 native inter gi0
banner login # Authenticate yourself! #
! Supports #, $ and % to delimit banners, and multiline banner motd $ Attention! We will be having scheduled system maintenance on this device. $