VLT proxy gateway enables one VLT domain to act as proxy gateway for another VLT domain when a host or virtual machine is moved from one VLT domain to the other VLT domain.
The following image depicts a sample topology in which VLT proxy gateway is configured.
Dell-1 and Dell-2 constitute VLT domain 120. Dell-3 and Dell-4 constitute VLT domain 110. These two VLT domains are connected using a VLT LAG P0 50. To know how to configure the interfaces in VLT domains, see the Configuring VLT section.
vlt domain 120 peer-link port-channel 120 back-up destination 10.1.1.3 primary-priority 4096 system-mac mac-address 02:01:e8:d8:93:e3 unit-id 0 peer-routing ! proxy-gateway static remote-mac-address 00:01:e8:8b:ff:4f remote-mac-address 00:01:e8:d8:93:04
The MAC addresses, configured using the remote-mac-address command, belong to Dell-3 and Dell-4.
interface TenGigabitEthernet 0/8 description "To DELL-3 10Gb" no ip address interface TenGigabitEthernet 0/9 description "To DELL-3 10Gb" no ip address ! port-channel-protocol LACP port-channel 50 mode active no shutdown interface Port-channel 50 description "mVLT port channel to DELL-3" no ip address switchport no spanning-tree vlt-peer-lag port-channel 50 no shutdown
Note that on the inter-domain link, the switchport command is enabled. On a VLTi link between VLT peers in a VLT domain, the switchport command is not used.
VLAN 100 is used as the OSPF peering VLAN between Dell-1 and Dell-2.
interface Vlan 100 description OSPF Peering VLAN to Dell-2 ip address 10.10.100.1/30 ip ospf network point-to-point no shutdown
VLAN 101 is used as the OSPF peering VLAN between the two VLT domains.
interface Vlan 101 description ospf peering vlan across VLTPG_Po50 ip address 10.10.101.1/30 tagged Port-channel 50 ip ospf network point-to-point no shutdown
The following sequence of commands represent the OSPF configuration on Dell-1.
router ospf 1 router-id 4.4.4.4 network 10.10.100.0/30 area 0 network 10.10.101.0/30 area 0
The following output shows that Dell-2 and VLT domain 110 form OSPF neighborship with Dell-1.
Dell-1#show ip ospf neighbor ! Neighbor ID Pri State Dead Time Address Interface Area 2.2.2.2 1 FULL/ - 00:00:39 10.10.100.2 Vl 100 0 3.3.3.3 1 FULL/ - 00:00:32 10.10.101.2 Vl 101 0
vlt domain 120 peer-link port-channel 120 back-up destination 10.1.1.2 primary-priority 24576 system-mac mac-address 02:01:e8:d8:93:e3 unit-id 1 peer-routing proxy-gateway static remote-mac-address 00:01:e8:8b:ff:4f remote-mac-address 00:01:e8:d8:93:04
The MAC addresses, configured using the remote-mac-address command, belong to Dell-3 and Dell-4.
interface Vlan 100 description OSPF peering VLAN to Dell-1 ip address 10.10.100.2/30 ip ospf network point-to-point no shutdown
The following is the OSPF configuration on Dell-2.
router ospf 1 router-id 2.2.2.2 network 10.10.100.0/30 area 0
The following output shows that Dell-1 forms OSPF neighborship with Dell-2.
Dell-2#sh ip ospf nei Neighbor ID Pri State Dead Time Address Interface Area 4.4.4.4 1 FULL/ - 00:00:33 10.10.100.1 Vl 100 0
vlt domain 110 peer-link port-channel 110 back-up destination 10.1.1.1 primary-priority 4096 system-mac mac-address 02:01:e8:d8:93:02 unit-id 0 peer-routing ! proxy-gateway static remote-mac-address 00:01:e8:d8:93:07 remote-mac-address 00:01:e8:d8:93:e5
These MAC addresses are the system L2 interface addresses for each switch at the remote site, Dell-1 and Dell-2.
interface TenGigabitEthernet 0/8 description "To Dell-1 10Gb" no ip address interface TenGigabitEthernet 0/9 description "To Dell-1 10Gb" no ip address ! port-channel-protocol LACP port-channel 50 mode active no shutdown ! interface Port-channel 50 description "mVLT port channel to Dell-1" no ip address switchport no spanning-tree (STP is disabled between sites) vlt-peer-lag port-channel 50 no shutdown interface Vlan 101 description ospf peering vlan across VLTPG_Po50 ip address 10.10.101.2/30 tagged Port-channel 50 ip ospf network point-to-point no shutdown ! interface Vlan 102 description ospf peering vlan to DELL-4 ip address 10.10.102.1/30 ip ospf network point-to-point no shutdown
The following is the OSPF configuration on Dell-3.
router ospf 1 router-id 3.3.3.3 network 10.10.101.0/30 area 0 network 10.10.102.0/30 area 0
The following output shows that Dell-4 and VLT domain 120 form OSPF neighborship with Dell-3.
Dell-3#sh ip ospf nei ! Neighbor ID Pri State Dead Time Address Interface Area 4.4.4.4 1 FULL/ - 00:00:33 10.10.101.1 Vl 101 0 1.1.1.1 1 FULL/ - 00:00:34 10.10.102.2 Vl 102 0
vlt domain 110 peer-link port-channel 110 back-up destination 10.1.1.0 primary-priority 24576 system-mac mac-address 02:01:e8:d8:93:02 unit-id 1 peer-routing ! proxy-gateway static remote-mac-address 00:01:e8:d8:93:07 remote-mac-address 00:01:e8:d8:93:e5
These MAC addresses are the system L2 interface addresses for each switch at the remote site, Dell-1 and Dell-2.
interface Vlan 102 description ospf peering vlan to DELL-3 ip address 10.10.102.2/30 ip ospf network point-to-point no shutdown
The following is the OSPF configuration on Dell-4.
router ospf 1 router-id 1.1.1.1 network 10.10.102.0/30 area 0
The following output shows that Dell-4 forms OSPF neighborship with Dell-3.
ELEM-2#sh ip ospf nei ! Neighbor ID Pri State Dead Time Address Interface Area 3.3.3.3 1 FULL/ - 00:00:32 10.10.102.1 Vl 102
With the above configuration, the two VLT domains act as VLT proxy gateways for any host that is moved from one VLT domain to another.
