Vrf-Lite; Configure Vrf-Lite - Cisco NCS 540 Series Configuration Manual

MPLS L3VPN Overview
RP/0/RP0/CPU0:router(config-static-afi)#
Enables an IPv4 address family.
Step 4 A.B.C.D/length next-hop
Example:
RP/0/RP0/CPU0:router(config-static-afi)# 10.10.10.10/32 10.9.9.9
Enters the address of the destination router (including IPv4 subnet mask).
Step 5
Use the commit or end command.
commit - Saves the configuration changes and remains within the configuration session.
end - Prompts user to take one of these actions:
• Yes - Saves configuration changes and exits the configuration session.
• No - Exits the configuration session without committing the configuration changes.
• Cancel - Remains in the configuration mode, without committing the configuration changes.

VRF-lite

VRF-lite is the deployment of VRFs without MPLS. VRF-lite allows a service provider to support two or
more VPNs with overlapping IP addresses. With this feature, multiple VRF instances can be supported in
customer edge devices.
VRF-lite interfaces must be Layer 3 interface and this interface cannot belong to more than one VRF at any
time. Multiple interfaces can be part of the same VRF, provided all of them participate in the same VPN.

Configure VRF-lite

Consider two customers having two VPN sites each, that are connected to the same PE router. VRFs are used
to create a separate routing table for each customer. We create one VRF for each customer (say, vrf1 and vrf2)
and then add the corresponding interfaces of the router to the respective VRFs. Each VRF has its own routing
table with the interfaces configured under it. The global routing table of the router does not show these
interfaces, whereas the VRF routing table shows the interfaces that were added to the VRF. PE routers exchange
routing information with CE devices by using static routing or a routing protocol such as BGP or RIP.
To summarize, VRF-lite configuration involves these main tasks:
• Create VRF
• Configure VRF under the interface
• Configure VRF under routing protocol
Configuration Example
• Create VRF:
L3VPN Configuration Guide for Cisco NCS 540 Series Routers, IOS XR Release 6.3.x
VRF-lite
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