The Net

make sure all the cabling are fine and working, show CDP should be able to show all it's neighbor set all the connected port above to be a trunking port ex using int range command on CORE1 to set trunk on int Gi1/1 until Gi1/3 CORE1(config)#interface range gigabitEthernet 1/1 - 3 CORE1(config-if-range)#switchport trunk encapsulation dot1q CORE1(config-if-range)#switchport mode trunk configure etherchannel between CORE1 and CORE2 interface GigabitEthernet1/1 (same for Gi1/2)  switchport  switchport trunk encapsulation dot1q  switchport mode trunk  no ip address  channel-protocol lacp  channel-group 64 mode active end this will automatically create etherchannel, Po64, make sure all the attribute in physical port applied the same to the port channel interface Port-channel64  switchport  switchport trunk encapsulation dot1q  switchport mode trunk  no ip address end *once you start your switch, check the name, if ' router>...

R0------------------------------------------------------------------------------------------------- interface Serial0/1  ip address 172.16.1.2 255.255.255.252  clock rate 64000 ! interface Serial0/2  ip address 172.16.2.2 255.255.255.252  clock rate 64000 ! interface Serial0/3  ip address 172.16.3.2 255.255.255.252  clock rate 64000 ! router ospf 1  log-adjacency-changes  network 172.16.1.0 0.0.0.3 area 0  network 172.16.2.0 0.0.0.3 area 0  network 172.16.3.0 0.0.0.3 area 0 R1------------------------------------------------------------------------------------------------- interface FastEthernet0/0  ip address 192.168.1.1 255.255.255.0  duplex auto  speed auto interface Serial0/0  ip address 172.16.1.1 255.255.255.252 ! router ospf 1  log-adjacency-changes   redistribute rip subnets  network 172.16.1.0 0.0.0.3 area 0 ! router rip  version 2   redistrib...

ip default-network ip route ip default-gateway this example we’ll use RIP, you can also use EIGRP but not OSPF prepare the network R1 interface FastEthernet0/0 ip address 10.1.1.1 255.255.255.0 duplex auto speed auto ! interface Serial0/0 ip address 192.168.1.1 255.255.255.0 clock rate 64000 ! interface Serial0/1 ip address 172.16.1.1 255.255.255.0 clock rate 64000 ! router rip network 172.16.0.0 network 192.168.1.0 R2 interface Serial0/0 ip address 192.168.1.2 255.255.255.0 ! router rip network 172.16.0.0 network 192.168.1.0 R3 interface Serial0/0 ip address 172.16.1.2 255.255.255.0 ! router rip network 172.16.0.0 make sure R1, R2 and R3 learn all the advertised interfaces and RIP working fine by pinging from one to other interfaces R1>sh ip rou R    99.0.0.0/8 [120/1] via 192.168.1.2, 00:00:16, Serial0/0 ...