The switch supports what is termed as VRF Lite. Lite conveys the fact that the switch does not use Multiprotocol Label Switching (MPLS) for VRF; VRF Lite is a device virtualization feature, not a network-wide virtualization feature.
Use VRF Lite to offer networking capabilities and traffic isolation to customers that operate over the same node (router). Each virtual router emulates the behavior of a dedicated hardware router; the network treats each virtual router as a separate physical router. In effect, you can perform the functions of many routers using a single platform that runs VRF Lite. The result is a substantial reduction in the cost associated with providing routing and traffic isolation for multiple clients.
With multicast virtualization for IPv4, the switch can function as multiple virtual multicast routers.
The following figure shows one platform acting as multiple virtual routers, each serving a different customer network.
A switch can support many virtual routers. Each virtual router instance is called a VRF instance. A VRF represents a single instance of a virtual router. Each instance maintains its own routing table. The term Multiple Virtual Router (MVR) is sometimes used to represent a router that contains many VRF instances.
The IPv6 Virtualization functionality adds IPv6 support on VRFs and Layer 3 VSNs. Each VRF instance has its own IPv6 interfaces, IPv6 address space, IPv6 routing table, and IPv6 global parameters. For more information on Layer 3 VSN, see Layer 3 VSN Configuration.
The Global Router, VRF 0, is the first instance of the router. When the system starts, it creates VRF 0 by default. VRF 0 provides all non-virtual and traditional routing services. You cannot delete this instance. You can create and configure other VRF instances, if required.
VRF 0 is the only VRF that you can log into through CLI. CLI requires you to specify the VRF when you enter commands.
You can associate one VRF instance with many IPv4 or IPv6 interfaces. These interfaces are unique for each VRF instance. An interface is an entity with an IPv4 or IPv6 address that has the following characteristics:
A unique association with a VLAN.
A unique association with a brouter, if not associated with a VLAN
A unique association with a circuit
A VLAN can only be associated with a single VRF instance.
Note
You cannot associate a VLAN or port and a VRF instance if the VLAN or port has an IPv4 or IPv6 address. You must first associate the port and VRF instance and then you can configure the IPv4 or IPv6 address.
Use the boot config flag vrf-scaling command, on supported switches, to increase the total number of supported VRFs. For more information on route scaling, see VOSS Release Notes.