Specifications

mpls l2transport route
MP-181
Cisco IOS Multiprotocol Label Switching Command Reference
January 2010
Usage Guidelines A Multiprotocol Label Switching (MPLS) VC runs across an MPLS cloud to connect interfaces on two
PE routers.
Use this command on each PE router to route packets across the MPLS cloud to the interface of the other
PE ro
uter. Specify the LDP IP address of the other PE router for the destination parameter. Do not
specify the IP address of the router from which you are issuing the command.
You can choose any number for the VC ID. However, the VC ID must be unique per pair of routers.
T
herefore, in large networks, it may be necessary to track the VC ID assignments to ensure that a VC ID
does not get assigned twice.
Cisco 7600 Series Routers
Cisco 7600 series routers equipped with a Supervisor Engine 2 must be equipped with either an optical
services module (OSM) or a FlexWAN port adapter that is facing the MPLS network with a Layer 2
Et
hernet port (non-OSM) facing the customer.
The mpls l2
transport route command enables the virtual connection used to route the VLAN packets.
The types of virtual connections used are as follows:
• VC Type 4—Allows all the traffic in a VLAN to use a single VC across the MPLS network.
• VC Type 5—Allows all traffic on a port to share a single VC across the MPLS network.
During the VC setup, VC type 5 is advertised. If the p
eer advertises VC type 4, the VC type is changed
to type 4 and the VC is restarted. The change only happens from type 5 to type 4 and never from type 4
to
type 5.
An MPLS VLAN virtual circuit in Layer 2 runs across an MPLS cloud to connect the VLAN interfaces
on t
wo PE routers.
Use the mpls l2
transport route command on the VLAN interface of each PE router to route the VLAN
packets in Layer 2 across the MPLS cloud to the VLAN interface of the other PE router. Specify the IP
ad
dress of the other PE router for the destination parameter. Do not specify the IP address of the router
from which you are issuing the command.
You can choose any value for the virtual-connection ID. However, the virtual-circuit ID must be unique
t
o each virtual connection. In large networks, you may need to track the virtual-connection ID
assignments to ensure that a virtual-connection ID does not get assigned twice.
The routed virtual connections are supported on the main interfaces, not subinterfaces.
Examples The following examples show how to enable routing of MPLS packets over a specified VC. Two routers
na
med PE1 and PE2 establish a VC to transport packets. PE1 has IP address 172.16.0.1, and PE2 has IP
address 192.168.0.1. The VC ID is 50.
ATM AAL5 over MPLS Example
At PE1, you issue the following commands:
PE1_Router(config)# interface atm5/0.100
PE1_Router(config-if)# pvc 1/200
PE1_Router(config-atm-vc)# encapsulation aal5
PE1_Router(config-atm-vc)# mpls l2transport route 192.168.0.1 50
At PE2, you issue the following commands:
PE2_Router(config)# interface atm5/0.100
PE2_Router(config-if)# pvc 1/200
PE2_Router(config-atm-vc)# encapsulation aal5
PE2_Router(config-atm-vc)# mpls l2transport route 172.16.0.1 50