interface GigabitEthernet1
 ip address dhcp
!
interface GigabitEthernet2
!
interface GigabitEthernet3
 ip address 198.51.100.1 255.255.255.0 secondary
 ip address 198.51.100.2 255.255.255.0
 ipv6 address 2001:db8:0:3::/64
!
interface GigabitEthernet4
!
interface Loopback999
 ip address 192.0.2.1 255.255.255.0
!
