Describes Layer 2 Virtual Private Network (L2VPN) connections that emulate LAN behavior across a Layer 2 switched, IP, or MPLS-enabled IP network.
Layer 2 Virtual Private Network (L2VPN) is a network connection that
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emulates LAN behavior across L2 switched, IP, or MPLS-enabled IP networks
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enables service providers to provide Layer 2 services to geographically disparate customer sites, and
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connects Ethernet devices as if they exist on a common LAN segment.
L2VPN in service provider networks
The L2VPN feature enables service providers (SPs) to provide Layer 2 services to geographically disparate customer sites. Typically, an SP uses an access network to connect the customer to the core network. On the router, this access network is typically Ethernet.
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.
On the router, an AC is an interface that is attached to an L2VPN component, such as a bridge domain.
The L2VPN feature enables users to implement different types of end-to-end services.
Switching takes place through local switching where traffic arriving on one AC is immediately sent out of another AC without passing through a pseudowire.