---

S1

enable
configure terminal
hostname S1
no ip domain-lookup
enable secret class
service password-encryption
line console 0
 password cisco
 login
exit
banner motd #Unauthorized access prohibited!#
interface vlan 1
 ip address 192.168.10.2 255.255.255.0
 no shutdown
exit
ip default-gateway 192.168.10.1
interface fa0/1
 description PC-A
exit
interface g0/1
 description To_R1
exit
interface range fa0/2-24
 shutdown
exit
interface g0/2
 shutdown
exit
end
write



S2
enable
configure terminal
hostname S2
no ip domain-lookup
enable secret class
service password-encryption
line console 0
 password cisco
 login
exit
banner motd #Unauthorized access prohibited!#
interface vlan 1
 ip address 192.168.20.2 255.255.255.0
 no shutdown
exit
ip default-gateway 192.168.20.1
interface fa0/1
 description PC-B
exit
interface g0/1
 description To_R2
exit
interface range fa0/2-24
 shutdown
exit
interface g0/2
 shutdown
exit
end
write



R1


enable
configure terminal
hostname R1
no ip domain-lookup
enable secret class
service password-encryption
line console 0
 password cisco
 login
exit
banner motd #Unauthorized access prohibited!#
interface g0/0
 description LAN_to_S1
 ip address 192.168.10.1 255.255.255.0
 no shutdown
exit
interface g0/1
 description WAN_to_R2
 ip address 10.0.0.1 255.255.255.252
 no shutdown
exit
ip route 192.168.20.0 255.255.255.0 10.0.0.2
end
write




R2


enable
configure terminal
hostname R2
no ip domain-lookup
enable secret class
service password-encryption
line console 0
 password cisco
 login
exit
banner motd #Unauthorized access prohibited!#
interface g0/0
 description LAN_to_S2
 ip address 192.168.20.1 255.255.255.0
 no shutdown
exit
interface g0/1
 description WAN_to_R1
 ip address 10.0.0.2 255.255.255.252
 no shutdown
exit
ip route 192.168.10.0 255.255.255.0 10.0.0.1
end
write