Administrator Guide
network 192.168.20.0/29 area 0
passive-interface default
no passive-interface vlan 20
While the passive-interface default command prevents all interfaces from establishing an OSPF neighborship, the no passive-interface vlan
20 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 neighbor
Neighbor ID Pri State Dead Time Address Interface Area
172.17.1.1 1 FULL/DR 00:00:31 192.168.20.1 Vl 20 0
172.15.1.1 1 FULL/DROTHER 00:00:33 192.168.20.3 Vl 20 0
The 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 ospf
Destination Gateway Dist/Metric Last Change
----------- ------- ----------- -----------
O 2.2.2.2/24 via 192.168.20.3, Vl 20 110/2 02:15:25
O 3.3.3.2/24 via 192.168.20.3, Vl 20 110/2 02:15:25
O 4.4.4.2/24 via 192.168.20.3, Vl 20 110/2 02:15:25
O 172.15.1.1/32 via 192.168.20.3, Vl 20 110/2 02:15:25
O 172.16.1.2/32 via 192.168.20.1, Vl 20 110/1 02:15:25
The following output displays the MAC address of all interfaces in the system. All interfaces, physical and virtual, have the same MAC
address. This is the address used for peer routing.
Dell#2#show interfaces | grep Hardware
Hardware is DellEth, address is 90:b1:1c:f4:29:f3
Hardware is DellEth, address is 90:b1:1c:f4:29:f3
Hardware is DellEth, address is 90:b1:1c:f4:29:f3
Hardware 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 0
VlanId Mac Address Region Interface
20 90:b1:1c:f4:29:f3 STATIC Po 10
20 00:0d:bc:6e:93:00 DYNAMIC Po 1
20 ff:ff:ff:ff:ff:ff STATIC 00001
900 90:b1:1c:f4:29:f3 STATIC Po 10
900 ff:ff:ff:ff:ff:ff STATIC 00001
800 90:b1:1c:f4:29:f3 STATIC Po 10
800 ff:ff:ff:ff:ff:ff STATIC 00001
0 ff:ff:ff:ff:ff:ff STATIC 00001
0 90:b1:1c:f4:2c:bd LOCAL_DA 00001
0 90:b1:1c:f4:29:f3 LOCAL_DA 00001
The MAC addresses of the VLAN interfaces of both VLT peers are registered in the L2 CAM as LOCAL_DA addresses.
R1 Conguration
Conguration on Interfaces
R1#show run | find Loopback2
interface Loopback2
ip address 2.2.2.2 255.255.255.0
!
interface Loopback3
ip address 3.3.3.2 255.255.255.0
!
interface Loopback4
ip address 4.4.4.2 255.255.255.0
916
Virtual Link Trunking (VLT)