Cisco IOS VRF-Lite Network Topology Difference Between VRF and VRF-Lite Explained VRF (Virtual Routing and Forwarding) and VRF-Lite (also known as Multi-VRF CE or MVPN) are both technologies used in networking to create multiple virtual routing and forwarding instances within a single physical router. The main difference between the two is in the scope of their implementation. VRF is typically used in service provider networks, where it allows for multiple customers to share the same physical infrastructure while still maintaining separate and isolated routing domains. VRF-Lite, on the other hand, is typically used in enterprise networks, where it allows for multiple logical networks to be created within a single physical network infrastructure. In summary, VRF is used for service provider networks, and VRF-Lite is used for enterprise networks. Scenario Company A has just completed an M&A process and acquired Company B. As part of the post acquisition integration process the decision was made to move Company B's IT equipment into the datacenter hosting facility used by Company A.  However, there are some critical elements in Company B such as network addressing and routing that cannot be immediately changed and must stay in place. It is a must, at least in the near to medium term to keep the Company B Accounting and Finance systems separate and secured from other parts of the overall company network while still providing the necessary access to authorized users and their computers.  Additionally it was discovered that Company B uses the same network subnet as Company B for the uplink to the Company B main router.  This has further complicated the plan to consolidate the topology to just one main router (HQ_DC).  However, you have a plan to use VRF-Lite and some VLAN architecture to solve these challenges. Configuration These configuration steps will demonstrate the configuration for both Company A and Company B for completeness.  Obviously in the scenario much of Company A's infrastructure configuration would already be done. CompanyA Router CompanyA>enableCompanyA#configure terminalCompanyA(config)#interface gigabitEthernet 0/3CompanyA(config-if)#ip address 192.168.10.1 255.255.255.0CompanyA(config-if)#no shutdownCompanyA(config-if)#interface gigabitEthernet 0/0CompanyA(config-if)#ip address 172.16.0.1 255.255.255.252CompanyA(config-if)#no shutdownCompanyA(config-if)#exitCompanyA(config)#router eigrp 100CompanyA(config-router)#network 0.0.0.0 0.0.0.0CompanyA(config-router)#no auto-summaryCompanyA(config-router)#end CompanyB Router CompanyB>enableCompanyB#configure terminalCompanyA(config)#interface gigabitEthernet 0/3CompanyA(config-if)#ip address 192.168.20.1 255.255.255.0CompanyA(config-if)#no shutdownCompanyA(config-if)#interface gigabitEthernet 0/0CompanyA(config-if)#ip address 172.16.0.1 255.255.255.252CompanyA(config-if)#no shutdownCompanyA(config-if)#exitCompanyA(config)#router eigrp 100CompanyA(config-router)#network 0.0.0.0 0.0.0.0CompanyA(config-router)#no auto-summaryCompanyA(config-router)#end HQ_DC Router HQ_DC>enableHQ_DC#configure terminalHQ_DC(config)#ip vrf COMPANYAHQ_DC(config-vrf)#exitHQ_DC(config)#ip vrf COMPANYBHQ_DC(config-vrf)#exitHQ_DC(config)#interface gigabitEthernet 0/0HQ_DC(config-if)#ip address 172.16.0.2 255.255.255.252HQ_DC(config-if)#description COMPANYA main circuitHQ_DC(config-if)#ip vrf forwarding COMPANYAHQ_DC(config-if)#exitHQ_DC(config)#interface gigabitEthernet 0/1HQ_DC(config-if)#ip address 172.16.0.2 255.255.255.252HQ_DC(config-if)#description COMPANYB main circuitHQ_DC(config-if)#ip vrf forwarding COMPANYBHQ_DC(config-if)#exitHQ_DC(config)#interface gigabitEthernet 0/2HQ_DC(config-if)#no shutdownHQ_DC(config-if)#interface gigabitEthernet 0/2.100HQ_DC(config-subif)#description COMPANYA dc circuitHQ_DC(config-subif)#encapsulation dot1q 100HQ_DC(config-subif)#ip vrf forwarding COMPANYAHQ_DC(config-subif)#ip address 192.168.100.1 255.255.255.0HQ_DC(config-if)#interface gigabitEthernet 0/2.200HQ_DC(config-subif)#description COMPANYB dc circuitHQ_DC(config-subif)#encapsulation dot1q 200HQ_DC(config-subif)#ip vrf forwarding COMPANYBHQ_DC(config-subif)#ip address 192.168.200.1 255.255.255.0HQ_DC(config-subif)#exitHQ_DC(config)#router eigrp 1HQ_DC(config-router)#address-family ipv4 vrf COMPANYAHQ_DC(config-router-af)#network 0.0.0.0 0.0.0.0HQ_DC(config-router-af)#autonomous-system 100HQ_DC(config-router-af)#no auto-summaryHQ_DC(config-router-af)#exitHQ_DC(config-router)#address-family ipv4 vrf COMPANYBHQ_DC(config-router-af)#network 0.0.0.0 0.0.0.0HQ_DC(config-router-af)#autonomous-system 100HQ_DC(config-router-af)#no auto-summary HQ_DC_SW1 Switch HQ_DC_SW1>enableHQ_DC_SW1#configure terminalHQ_DC_SW1(config)#vlan 100HQ_DC_SW1(config-vlan)#name COMPANYAHQ_DC_SW1)config-vlan)#exitHQ_DC_SW1(config)#vlan 200HQ_DC_SW1(config-vlan)#name COMPANYBHQ_DC_SW1)config-vlan)#exitHQ_DC_SW1(config)#interface gigabitEthernet 0/2HQ_DC_SW1(config-if)#switchport trunk encapsulation dot1qHQ_DC_SW1(config-if)#switchport mode trunkHQ_DC_SW1(config-if)#switchport trunk allowed vlan 100,200HQ_DC_SW1(config-if)#interface gigabitEthernet 0/0HQ_DC_SW1(config-if)#switchport access vlan 100HQ_DC_SW1(config-if)#interface gigabitEthernet 0/1HQ_DC_SW1(config-if)#switchport access vlan 200HQ_DC_SW1(config-if)#exitHQ_DC_SW1(config)#interface vlan 100HQ_DC_SW1(config-if)#ip address 192.168.100.2 255.255.255.0HQ_DC_SW1(config-if)#exitHQ_DC_SW1(config)#interface vlan 200HQ_DC_SW1(config-if)#ip address 192.168.200.2 255.255.255.0 PCs and Servers PC1>ip 192.168.10.10/24 192.168.10.1 PC2>ip 192.168.20.20/24 192.168.20.1 COMPA_ACCT> ip address 192.168.100.10/24 192.168.100.1 COMPB_ACCT> ip address 192.168.200.20/24 192.168.200.1 Test and Verify Connectivity and Configuration GNS3 File vrf2.gns3