Virtual routing and forwarding configuration, Vrf overview, Vrf topology – Brocade Network OS Administrator’s Guide v4.1.1 User Manual
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Virtual Routing and Forwarding configuration
VRF overview
VRF (Virtual Routing and Forwarding) is a technology that controls information flow within a network by
isolating the traffic by partitioning the network into different logical VRF domains. This allows a single
router or switch to have multiple containers of routing tables or Forwarding Information Bases (FIB)
inside it, with one routing table for each VRF instance. This permits a VRF-capable router to function as
a group of multiple virtual routers on the same physical router. VRF, in conjunction with virtual private
network (VPN) solutions, guarantees privacy of information and isolation of traffic within a logical VRF
domain.
A typical implementation of a Virtual Routing and Forwarding instance (referred to as a VRF) are
designed to support Border Gateway Protocol (BGP) or Multiprotocol Label Switching (MPLS) VPNs,
whereas implementations of VRF-Lite (also referred to as Multi-VRF) typically are much simpler with
reduced scalability. The two VRF flavors have a lot in common but differ in the interconnect schemes,
routing protocols used over the interconnect, and also in VRF classification mechanisms.
VRF is supported on the Brocade VDX 8770 and VDX 6740 series platforms. The VDX 8770 supports
128 VRF instances and the VDX 6740 supports 32 VRF instances per physical switch.
Brocade Network OS 4.0.0 and later supports the VRF-Lite implementation. Unless otherwise noted, all
references to VRF in this document also apply to VRF-Lite.
VRF topology
This diagram illustrates a typical VRF topology with a single VCS comprising Customer 1 Edge,
Provider Edge, and Customer 2 Edge routers.
The orange and green ovals indicate two VPNs supporting two different customer sites. Both of them
have overlapping IP subnets; 100.100.100.0/24 and 100.100.200.0/24.
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