Cisco Systems 3560 Manual De Usuario

The Catalyst 3560 switch supports multiple VPN routing/forwarding (multi-VRF) instances in customer 
edge (CE) devices (multi-VRF CE) when the switch is running the IP services image. If you try to 
configure it on a switch running the IP base image, you see an error message. Multi-VRF CE allows a 
service provider to support two or more VPNs with overlapping IP addresses. On a switch running the 
IP base image, configuring multi-VRF-CE and EIGRP stub routing at the same time is not allowed.

The switch does not use Multiprotocol Label Switching (MPLS) to support VPNs. For information about 
MPLS VRF, refer to the Cisco IOS Switching Services Configuration Guide, Release 12.2 from the 
Cisco.com page under Documentation > Cisco IOS Software > 12.2 Mainline > Command 
References.

These sections contain this information:

Multi-VRF CE is a feature that allows a service provider to support two or more VPNs, where IP 
addresses can be overlapped among the VPNs. Multi-VRF CE uses input interfaces to distinguish routes 
for different VPNs and forms virtual packet-forwarding tables by associating one or more Layer 3 
interfaces with each VRF. Interfaces in a VRF can be either physical, such as Ethernet ports, or logical, 
such as VLAN SVIs, but an interface cannot belong to more than one VRF at any time. 

Multi-VRF CE interfaces must be Layer 3 interfaces.

Multi-VRF CE includes these devices:

Customer edge (CE) devices provide customers access to the service-provider network over a data 
link to one or more provider edge routers. The CE device advertises the site’s local routes to the 
router and learns the remote VPN routes from it. A Catalyst 3560 switch can be a CE.

Provider edge (PE) routers exchange routing information with CE devices by using static routing or 
a routing protocol such as BGP, RIPv2, OSPF, or EIGRP. The PE is only required to maintain VPN 
routes for those VPNs to which it is directly attached, eliminating the need for the PE to maintain 
all of the service-provider VPN routes. Each PE router maintains a VRF for each of its directly 
connected sites. Multiple interfaces on a PE router can be associated with a single VRF if all of these 
sites participate in the same VPN. Each VPN is mapped to a specified VRF. After learning local 
VPN routes from CEs, a PE router exchanges VPN routing information with other PE routers by 
using internal BGP (IBPG).