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ATM Switch Router Software Configuration Guide
OL-7396-01
Chapter 16
Configuring Tag Switching and MPLS
MPLS VPNs
processor on behalf of the interfaces. The VPN interfaces forward all IP packets they receive from the
CE device to the enhanced ATM router module. The enhanced ATM router module processes the packets
and forwards them to the appropriate outgoing port.
Note
IPX routing and VPN processing are incompatible. You must remove all IPX routing configuration from
the Fast Ethernet interface with which you wish to link, and from all Fast Ethernet interfaces on the
interface module controlled by the same Ethernet processor interface, before configuring VPN. Each
Ethernet processor interface controls four Fast Ethernet interfaces on the interface module. On a 16-port
Fast Ethernet interface module, ports 0 through 3 are controlled by one Ethernet processor interface,
ports 4 through 7 by another, and so forth. For example, if you want to configure an MPLS control link
on Fast Ethernet interface 3/0/1, you must remove all IPX configuration from interfaces 3/0/0, 3/0/1,
3/0/2, and3/0/3.
Configuring VPN on Fast Ethernet Interface
To configure a Fast Ethernet interface as part of an MPLS VPN, perform the following steps:
Fast Ethernet Interface Example
The following example shows how to configure the Fast Ethernet interface connected to the customer
equipment from the PE ATM switch router and links it to the enhanced ATM router module for
processing:
8540-ATM-PE1#
configure terminal
8540-ATM-PE1(conf)#
interface FastEthernet0/0/0
8540-ATM-PE1(conf-if)#
ip vrf forwarding vpn1
8540-ATM-PE1(conf-if)#
ip address 12.0.0.2 255.0.0.0
8540-ATM-PE1(conf-if)#
mpls-forwarding interface ATM2/0/0
8540-ATM-PE1(conf-if)#
end
8540-ATM-PE1#
Note
Subinterfaces on a Fast Ethernet interface cannot be linked to enhanced ATM router module interfaces.
Note
MPLS can be configured on the Fast Ethernet interface using the
mpls-forwarding interface
command
and by linking it to an enhanced ATM router module interface using the
mpls-forwarding interface
command. The enhanced ATM router module interface should be UP for MPLS processing to work.
Command
Purpose
Step 1
Switch(config)#
interface atm
card
/
subcard
/
port
Switch(config-if)#
Selects the Fast Ethernet interface.
Step 2
Switch(config-if)#
ip vrf forwarding
vrf-name
Associates a VRF with an interface or
subinterface.
Step 3
Switch(config-if)#
ip address
ip-address mask
Configures the IP and subnetwork address.
Step 4
Switch(config-if)#
mpls-forwarding interface
atm
card
/
subcard
/
port
Links a Fast Ethernet interface to an enhanced
ATM router module interface, which performs
MPLS processing for a Fast Ethernet interface