Improved L2Vpn Access To L3Vpn Or Ip Backbone - HP HPE FlexNetwork MSR Router Series Configuration Manual

backbone through PE 3. PE 3 acts as a PE in the MPLS L3VPN/IP backbone and as a CE in the
MPLS L2VPN at the same time.
A packet from VPN site 1 to VPN site 2 is forwarded as follows:
1. A user in VPN site 1 sends a packet to PE 1.
2. PE 1 adds an MPLS label to the packet and sends the packet through a PW to PE 2.
3. PE 2 removes the MPLS label from the packet to obtain the original Layer 2 packet, and sends
the packet to the connected CE (PE 3).
4. PE 3 looks up the routing table, and forwards the packet to the destination through the MPLS
L3VPN or IP backbone.
In the conventional networking mode, two devices are required to connect the MPLS L2VPN with the
MPLS L3VPN or IP backbone (PE 2 and PE 3 in this example). One (PE 2) is required for terminating
the MPLS L2VPN, and the other (PE 3) is required for accessing the MPLS L3VPN or IP backbone.

Improved L2VPN access to L3VPN or IP backbone

In the improved networking mode, the functions of the two devices that connect the MPLS L2VPN
and the MPLS L3VPN or IP backbone can be implemented on one device. Thus, you can reduce the
number of devices to be deployed, and lower the networking cost and the network deployment
complexity.
Figure 131 Network diagram
VPN 1
Site 1
CE 1
As shown in
MPLS L3VPN or IP backbone. PE-agg terminates the MPLS L2VPN and provides access to the
MPLS L3VPN or IP backbone.
Configure the PE-agg as follows so the PE-agg can implement the functions of both PE 2 and PE 3
in Figure 130:
1. Create a terminating virtual Ethernet (VE) interface on the PE-agg to terminate MPLS L2VPN
packets.
This interface is referred to as the VE-L2VPN (L2VE) interface. The functions and
configurations of the interface are similar to those of the terminating interface (Terminating int)
in Figure
Packet processing in PE-agg
Input interface
MPLS L2VPN
access network
PE 1
Figure 131, the PE Aggregation (PE-agg) device connects the MPLS L2VPN with the
130.
Output interface
VE-L2VPN VE-L3VPN
MPLS L3VPN/
IP backbone
PE-agg
499
PE 4
VPN 1
CE 2
Site 2