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Cisco 10000 Series Router Software Configuration Guide
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Chapter 4 Configuring Multiprotocol Label Switching
Half-Duplex VRF
Associating VRFs
After you define and configure the VRFs on the PE routers, associate each VRF with:
•
An interface or subinterface, or
•
A virtual template interface
The virtual template interface is used to create and configure a virtual access interface (VAI). For
information about configuring a virtual template interface, see the
“Configuring a Virtual Template
Interface” section on page 3-17
.
To associate a VRF, enter the following commands on the PE router beginning in interface configuration
mode:
Example 4-9
associates the VRF named vpn1 with the Virtual-Template1 interface and specifies the
downstream VRF named D.
Example 4-9
Associating a Downstream VRF with a Virtual Template Interface
Router(config)# interface Virtual-Template1
Router(config-if)# ip vrf forwarding vpn1 downstream D
Router(config-if)# ip unnumbered Loopback1
Router(config-if)# no peer default ip address
Router(config-if)# ppp authentication chap vpn1
Router(config-if)# ppp authorization vpn1
Router(config-if)# ppp accounting vpn1
Command
Purpose
Step 1
Router(config-if)#
ip vrf forwarding
vrf-name
Associates an interface with the VRF you specify.
vrf-name
is the name of the VRF associated with the interface.
Step 2
Router(config-if)#
ip unnumbered
type number
Enables IP processing on an interface without assigning an
explicit IP address to the interface.
The
type
and
number
arguments are the type and number of
another interface on which the router has an assigned IP
address. It cannot be another unnumbered interface.
Note
The Cisco 10000 series router supports only
unnumbered interfaces for the Half-Duplex VRF
feature.
Step 3
Router(config-if)#
exit
Returns to global configuration mode.
Step 4
Router(config)#
interface virtual-template
number
Creates a virtual template interface and enters interface
configuration mode.
Step 5
Router(config-if)#
ip vrf forwarding
vrf-name1
[
downstream
vrf-name2
]
Associates a virtual template interface with the VRF you
specify.
The
vrf-name1
argument is the name of the VRF associated
with the virtual template interface.
The
vrf-name2
argument is the name of the downstream VRF
into which the PPP peer route and all of the per-user routes from
the AAA server are installed. If a AAA server is used, the AAA
server provides the VRF membership; you do not need to
configure the VRF members on the virtual templates.