network 192.168.20.0/29 area 0passive-interface defaultno passive-interface vlan 20While the passive-interface default command prevents all interfaces from establishing an OSPF neighborship, the no passive-interface vlan20 command allows the interface for VLAN 20, the OSPF peering VLAN, to establish OSPF adjacencies.The following output displays that Dell-1 forms neighborship with Dell-2 and R1.Dell-2#show ip ospf neighborNeighbor ID Pri State Dead Time Address Interface Area172.17.1.1 1 FULL/DR 00:00:31 192.168.20.1 Vl 20 0172.15.1.1 1 FULL/DROTHER 00:00:33 192.168.20.3 Vl 20 0The following output displays the routes learned using OSPF. Dell-2 also learns the routes to the loopback addresses on R1 through OSPF.Dell-2#show ip route ospfDestination Gateway Dist/Metric Last Change----------- ------- ----------- -----------O 2.2.2.2/24 via 192.168.20.3, Vl 20 110/2 02:15:25O 3.3.3.2/24 via 192.168.20.3, Vl 20 110/2 02:15:25O 4.4.4.2/24 via 192.168.20.3, Vl 20 110/2 02:15:25O 172.15.1.1/32 via 192.168.20.3, Vl 20 110/2 02:15:25O 172.16.1.2/32 via 192.168.20.1, Vl 20 110/1 02:15:25The following output displays the MAC address of all interfaces in the system. All interfaces, physical and virtual, have the same MACaddress. This is the address used for peer routing.Dell#2#show interfaces | grep HardwareHardware is DellEth, address is 90:b1:1c:f4:29:f3Hardware is DellEth, address is 90:b1:1c:f4:29:f3Hardware is DellEth, address is 90:b1:1c:f4:29:f3Hardware is DellEth, address is 90:b1:1c:f4:29:f3(Output truncated for brevity)Verify if peer routing has populated the CAM table with the correct information using the show cam mac command.Dell#2#sh cam mac stack-unit 0 port-set 0VlanId Mac Address Region Interface20 90:b1:1c:f4:29:f3 STATIC Po 1020 00:0d:bc:6e:93:00 DYNAMIC Po 120 ff:ff:ff:ff:ff:ff STATIC 00001900 90:b1:1c:f4:29:f3 STATIC Po 10900 ff:ff:ff:ff:ff:ff STATIC 00001800 90:b1:1c:f4:29:f3 STATIC Po 10800 ff:ff:ff:ff:ff:ff STATIC 000010 ff:ff:ff:ff:ff:ff STATIC 000010 90:b1:1c:f4:2c:bd LOCAL_DA 000010 90:b1:1c:f4:29:f3 LOCAL_DA 00001The MAC addresses of the VLAN interfaces of both VLT peers are registered in the L2 CAM as LOCAL_DA addresses.R1 ConfigurationConfiguration on InterfacesR1#show run | find Loopback2interface Loopback2ip address 2.2.2.2 255.255.255.0!interface Loopback3ip address 3.3.3.2 255.255.255.0!interface Loopback4ip address 4.4.4.2 255.255.255.0Virtual Link Trunking (VLT) 1015
