Layer 2 Vpn On Ethernet Interfaces - Cisco 6000 Series Configuration Manual

Configuring Ethernet Interfaces
Table 4: Fast Ethernet Default Configuration Values
Parameter
MAC accounting
Duplex operation
MTU
Interface speed
Auto-negotiation

Layer 2 VPN on Ethernet Interfaces

Layer 2 Virtual Private Network (L2VPN) connections emulate the behavior of a LAN across an L2 switched,
IP or MPLS-enabled IP network, allowing Ethernet devices to communicate with each other as if they were
connected to a common LAN segment.
Traffic from the customer travels over this link to the edge of the SP core network. The traffic then tunnels
through an L2VPN over the SP core network to another edge router. The edge router sends the traffic down
another attachment circuit (AC) to the customer's remote site.
The L2VPN feature enables users to implement different types of end-to-end services.
Cisco IOS XR software supports a point-to-point end-to-end service, where two Ethernet circuits are connected
together. An L2VPN Ethernet port can operate in one of two modes:
• Port Mode—In this mode, all packets reaching the port are sent over the PW (pseudowire), regardless
• VLAN Mode—Each VLAN on a CE (customer edge) or access network to PE (provider edge) link can
Switching can take place in three ways:
• AC-to-PW—Traffic reaching the PE is tunneled over a PW (and conversely, traffic arriving over the PW
• Local switching—Traffic arriving on one AC is immediately sent out of another AC without passing
• PW stitching—Traffic arriving on a PW is not sent to an AC, but is sent back into the core over another
Keep the following in mind when configuring L2VPN on an Ethernet interface:
• L2VPN links support QoS (Quality of Service) and MTU (maximum transmission unit) configuration.
• If your network requires that packets are transported transparently, you may need to modify the packet's
Use the show interfaces command to display AC and PW information.
Interface and Hardware Component Configuration Guide for Cisco NCS 6000 Series Routers, IOS XR Release 6.4.x
Configuration File Entry
mac-accounting
duplex full
duplex half
mtu
speed
negotiation auto
of any VLAN tags that are present on the packets. In VLAN mode, the configuration is performed under
the l2transport configuration mode.
be configured as a separate L2VPN connection (using either VC type 4 or VC type 5). In VLAN mode,
the configuration is performed under the individual subinterface.
is sent out over the AC). This is the most common scenario.
through a pseudowire.
PW.
destination MAC (Media Access Control) address at the edge of the Service Provider (SP) network. This
prevents the packet from being consumed by the devices in the network.
Default Value
off
Auto-negotiates duplex operation
1500 bytes
100 Mbps
disable
Layer 2 VPN on Ethernet Interfaces
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