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Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide
OL-13270-06
Chapter 39 Configuring IP Unicast Routing
Configuring Multi-VRF CE
•
When an egress PE receives a packet from the network, it strips the label and uses the label to
identify the correct VPN routing table. Then it performs the normal route lookup. When a route is
found, it forwards the packet to the correct adjacency.
•
When a CE receives a packet from an egress PE, it uses the input policy label to look up the correct
VPN routing table. If a route is found, the PE forwards the packet within the VPN.
To configure VRF, you create a VRF table and specify the Layer 3 interface associated with the VRF.
Then you configure the routing protocols in the VPN and between the CE and the PE. BGP is the
preferred routing protocol used to distribute VPN routing information across the provider’s backbone.
The multi-VRF CE network has these major components:
•
VPN route target communities—lists of all other members of a VPN community. You need to
configure VPN route targets for each VPN community member.
•
Multiprotocol BGP peering of VPN community PE routers—propagates VRF reachability
information to all members of a VPN community. You need to configure BGP peering in all PE
routers within a VPN community.
•
VPN forwarding—transports all traffic between all VPN community members across a VPN
service-provider network.
Default Multi-VRF CE Configuration
Table 39-14
shows the default multi-VRF CE configuration.
Multi-VRF CE Configuration Guidelines
To use multi-VRF CE, you must have the IP services feature set enabled on your switch.
These are considerations when configuring multi-VRF CE in your network:
•
A switch with multi-VRF CE is shared by multiple customers, and each customer has its own routing
table.
•
Because customers use different VRF tables, the same IP addresses can be reused. Overlapped IP
addresses are allowed in different VPNs.
•
Multi-VRF CE lets multiple customers share the same physical link between the PE and the CE.
Trunk ports with multiple VLANs separate packets among customers. Each customer has its own
VLAN.
•
Multi-VRF CE does not support all MPLS-VRF functionality. It does not support label exchange,
LDP adjacency, or labeled packets.
Table 39-14
Default Multi-VRF CE Configuration
Feature
Default Setting
VRF
Disabled. No VRFs are defined.
Maps
No import maps, export maps, or route maps are defined.
VRF maximum routes
Fast Ethernet switches: 8000
Gigabit Ethernet switches: 12,000.
Forwarding table
The default for an interface is the global routing table.