Juniper BGP - CONFIGURATION GUIDE V 11.1.X Configuration Manual page 558

JUNOSe 11.1.x BGP and MPLS Configuration Guide
layer 2 processing is required on the remaining layer 2 frames. After PE2 processes
the Ethernet layer 2 frames, they are forwarded to CE2.
Traffic arriving at PE1 from pseudowires is distributed across all the member links
of the LAG. The hashing algorithm, based on the VLAN identifier and source and
destination MAC addresses, is used to determine the physical link to which the packets
must be forwarded.
If you configure the Martini tunnel directly over LAG in the same topology as shown
in Figure 1, packet processing at PE1 remains the same as the case described. The
only difference is in processing the hash algorithm, which uses only the source and
destination MAC addresses, and not the VLAN identifier, to determine the physical
link for transmission of MPLS packets transmitted from the pseudowires.
If IP traffic is being transmitted from CE1, which is not designated for the MPLS
L2VPN tunnel, the packets arrive at an interface that is different from the one used
for MPLS traffic, VLAN2. This behavior occurs because the VLAN interface used for
transmission of IP traffic must be different from that used for MPLS traffic.
The MPLS shim interface can be configured directly over LAG or stacked on a VLAN
interface over LAG. For more information on the guidelines to be followed when you
configure the MPLS shim interface to enable MPLS Martini circuits to use LAG on the
CE-side devices, see "Multiple Layer 2 Services over MPLS" on page 515.
Related Topics
Ethernet Raw Mode Encapsulation for Martini Layer 2 Transport Overview
An Ethernet pseudowire carries Ethernet/802.3 traffic over an MPLS network. JUNOSe
software enables Ethernet traffic to be transmitted over Martini circuits (cross-connect
virtual circuits) on ES2 4G line modules (LMs), GE-2 LMs, GE/FE LMs, ES2 10G LMs,
ES2 10G Uplink LMs, and ES2 10G ADV LMs. In previous releases, the transfer of
Ethernet packets over MPLS-based pseudowire enabled service providers to provide
point-to-point layer 2 Ethernet connectivity between geographically remote customer
edge (CE) devices. This functionality enabled the following tasks to be performed on
received packets:
However, this mode of processing did not allow for:
522
Ethernet Raw Mode Encapsulation for Martini Layer 2 Transport Overview
MPLS L2VPN Tunnel over VLAN over LAG Configuration Example on page 547
MPLS L2VPN Tunnel over LAG Configuration Example on page 551
Removal of all V-LAN tags from layer 2 frames received from CE devices before
transmitting that frame to the pseudowire
Replacement of all V-LAN tags in layer 2 frames received from the pseudowire
with the configured VLAN tags on the local interface before sending the frame
to the CE device
Insertion of the inner V-LAN tag while sending layer 2 frames received from the
pseudowire to the CE device on a double-tagged interface
Identification of a particular VLAN tag in single-tagged or double-tagged packets
as the service-delimiting tag