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Cisco IOS Release 12.2(8)T
OSPF Sham-Link Support for MPLS VPN
Feature History
This document describes how to configure and use a sham-link to connect Virtual Private Network
(VPN) client sites that run the Open Shortest Path First (OSPF) protocol and share backdoor OSPF links
in a Multiprotocol Label Switching (MPLS) VPN configuration.
This document includes the following sections:
Feature Overview, page1
Supported Platforms, page 8
Supported Standards, MIBs, and RFCs, page 10
Prerequisites, page 10
Configuration Tasks, page10
Configuration Examples, page 12
Command Reference, page 12
Glossary, page 16

Feature Overview

Using OSPF in PE-CE Router Connections

In an MPLS VPN configuration, the OSPF protocol is one way you can connect customer edge (CE) routers
to service provider edge (PE) routers in the VPN backbone. OSPF is often used by customers that run OSPF
as their intrasite routing protocol, subscribe to a VPN service, and want to exchange routing information
between their sites using OSPF (during migration or on a permanent basis) over an MPLS VPN backbone.
Figure 1 shows an example of how VPN client sites that run OSPF can connect over an MPLS VPN
backbone.
Release Modification
12.2(8)T This feature was introduced.