Switch(config)# hostname SW1
SW1(config)# interface GigabitEthernet 0/0
SW1(config-if)# switchport trunk encapsulation dot1q
SW1(config-if)# switchport trunk allowed vlan 100,300
SW1(config-if)# switchport mode trunk
SW1(config-if)# description Link to R1

SW1(config-if)# interface GigabitEthernet 0/1
SW1(config-if)# switchport mode access
SW1(config-if)# switchport access vlan 100
SW1(config-if)# description Link to PC1

SW1(config-if)# interface GigabitEthernet 0/2
SW1(config-if)# switchport mode access
SW1(config-if)# switchport access vlan 300
SW1(config-if)# description Link to PC3

SW1(config)# vlan 100
SW1(config-vlan)# name IPsec_to_B
SW1(config-vlan)# vlan 300
SW1(config-vlan)# name Guest_Internet