Cisco 3825 - Manual (Page 33)

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Cisco 3825 Mobile Wireless Edge Router Software Configuration Guide
OL-15667-03
Chapter 1 Overview of the Cisco 3825 Mobile Wireless Edge Router
New Features in Cisco IOS Release 12.4(16)MR1
Ethernet over MPLS
The Ethernet over MPLS feature allows you to transport Ethernet traffic over MPLS networks. This
feature can be configured in the following two ways:
VLAN Mode
A VLAN is a switched network that is logically segmented by functions, project teams, or applications
regardless of the physical location of users.
To connect two VLAN networks in different locations, configure the PE routers at each end of the MPLS
backbone and add a point-to-point virtual connection (VC). Only two PE routers at the ingress and egress
points of the MPLS backbone have dedicated VCs to transport Layer 2 VLAN traffic.
Ethernet over MPLS in VLAN mode transports Ethernet traffic from a source 802.1Q VLAN to a
destination 802.1Q VLAN over a core MPLS network.
The following example configures Ethernet in VLAN mode:
Router> enable
Router# configure terminal
Router(config)# interface gigabitethernet 0/0.1
Router(config-subif)# encapsulation dot1q 100
Router(config-subif)# xconnect 10.0.0.1 123 encapsulation mpls
Note Ethernet over MPLS in VLAN mode must be configured on subinterfaces.
Port Mode
Port mode allows a frame coming into an interface to be packed into an MPLS packet and transported
over the MPLS backbone to an egress interface. The entire Ethernet frame without the preamble or a
frame check sequence (FCS) is transported as a single packet.
To configure in port mode, use the xconnect command in the interface configuration mode and specify
the destination address and the VC ID. The syntax of the xconnect command is the same for all other
transport types. Each interface is associated with one unique PW VC label.
When configuring Ethernet over MPLS in port mode, use the following guidelines:
– The pseudowire (PW) VC type is set to Ethernet.
– Port mode and Ethernet VLAN mode are mutually exclusive. If you enable a main interface for
port-to-port transport, you cannot also enter commands on a subinterface.
The command output in the following example shows two VCs for Ethernet over MPLS:
Router# show mpls l2transport vc
Local intf Local circuit Dest address VC ID Status
------------- -------------------- --------------- ---------- ----------
Fa0/0.1 Eth VLAN 2 10.1.1.1 2 UP
Fa0/1 Ethernet 10.1.1.1 8 UP
VC 2 is in Ethernet VLAN mode. VC 8 is in Ethernet port mode.