hostname Core-R2
Core-R2(config)#
Core-R2(config)#no ip domain-lookup
Core-R2(config)#
Core-R2(config)#banner motd # Authorized Access Only - Core-R2 Router #
Core-R2(config)#
Core-R2(config)#interface GigabitEthernet0/0/0
Core-R2(config-if)#
Core-R2(config-if)#description Core LAN Segment to S2
Core-R2(config-if)#
Core-R2(config-if)#ip address 192.168.20.1 255.255.255.0
Core-R2(config-if)#
Core-R2(config-if)#no shutdown

Core-R2(config-if)#
%LINK-5-CHANGED: Interface GigabitEthernet0/0/0, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0/0, changed state to up

Core-R2(config-if)#exit
Core-R2(config)#
Core-R2(config)#interface GigabitEthernet0/0/1
Core-R2(config-if)#
Core-R2(config-if)#description Transit WAN Link to Edge-R1
Core-R2(config-if)#
Core-R2(config-if)#ip address 10.0.0.2 255.255.255.252
Core-R2(config-if)#
Core-R2(config-if)#no shutdown

Core-R2(config-if)#
%LINK-5-CHANGED: Interface GigabitEthernet0/0/1, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0/1, changed state to up

Core-R2(config-if)#exit
Core-R2(config)#
Core-R2(config)#router ospf 1
Core-R2(config-router)#
Core-R2(config-router)#router-id 2.2.2.2
Core-R2(config-router)#
Core-R2(config-router)#network 10.0.0.0 0.0.0.3 area 0
Core-R2(config-router)#
Core-R2(config-router)#network 192.168.20.0 0.0.0.255 area 0
Core-R2(config-router)#
Core-R2(config-router)#exit
Core-R2(config)#
Core-R2(config)#end
%SYS-5-CONFIG_I: Configured from console by console

Core-R2#copy running-config startup-config
Destination filename [startup-config]?
Building configuration...
[OK]
00:32:09: %OSPF-5-ADJCHG: Process 1, Nbr 1.1.1.1 on GigabitEthernet0/0/1 from LOADING to FULL, Loading Done
configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
Core-R2(config)#
Core-R2(config)#router ospf 1
Core-R2(config-router)#
Core-R2(config-router)#passive-interface default
Core-R2(config-router)#
00:36:02: %OSPF-5-ADJCHG: Process 1, Nbr 1.1.1.1 on GigabitEthernet0/0/1 from FULL to DOWN, Neighbor Down: Interface down or detached

Core-R2(config-router)#no passive-interface GigabitEthernet0/0/1
Core-R2(config-router)#
Core-R2(config-router)#exit
Core-R2(config)#
Core-R2(config)#end