3Com Switch 8800 Configuration Guide Chapter 37 BGP/MPLS VPN Configuration37-7237.4.9 OSPF Multi-instance sham link Configuration ExampleI. Network requirementsAs shown in the following picture, a company connects to a WAN through OSPFmulti-instance function of a router. OSPF is bind to VPN1.MPLS VPN backbone runsbetween PEs and OSPF runs between PE and CE. Configure a sham link betweenPE1 and PE2 to ensure the traffic between CE1 and CE2 does not pass the backdoorlink that directly connects CE1 and CE2.II. Network diagramCE110.10.10.10CE220.20.20.2012.1.1.0/24PE1 PE33.3.3.3PE22.2.2.2VLAN20110.1.1.1/24(168.1.1.0/24)20.2.1.0/24VLAN20212.1.1.1/24MPLS VPN BackboneLoopBack0: 1.1.1.1LoopBack0: 2.2.2.2LoopBack0: 3.3.3.3VLAN20110.1.1.2/24VLAN203168.1.12.1/24VLAN202168.1.13.1/24(backdoor) sham linkLoopBack1:50.1.1.1LoopBack1:50.1.1.2LoopBack1:50.1.1.31.1.1.1VLAN203168.1.12.2/24VLAN202168.1.13.2/24VLAN202168.1.23.2/24VLAN201168.1.23.1/24VLAN20120.1.1.2/24VLAN20120.1.1.1/24VLAN20212.1.1.2/24CE110.10.10.10CE220.20.20.2012.1.1.0/24PE1 PE33.3.3.3PE22.2.2.2VLAN20110.1.1.1/24(168.1.1.0/24)20.2.1.0/24VLAN20212.1.1.1/24MPLS VPN BackboneLoopBack0: 1.1.1.1LoopBack0: 2.2.2.2LoopBack0: 3.3.3.3VLAN20110.1.1.2/24VLAN203168.1.12.1/24VLAN202168.1.13.1/24(backdoor) sham linkLoopBack1:50.1.1.1LoopBack1:50.1.1.2LoopBack1:50.1.1.31.1.1.1VLAN203168.1.12.2/24VLAN202168.1.13.2/24VLAN202168.1.23.2/24VLAN201168.1.23.1/24VLAN20120.1.1.2/24VLAN20120.1.1.1/24VLAN20212.1.1.2/24Figure 37-16 Network diagram for OSPF multi-instanceIII. Configuration procedure1) Configure PE1Enable MPLS and LDP.[PE1] mpls lsr-id 50.1.1.1[PE1] mpls[PE1-mpls] quit[PE1] mpls ldpConfigure VPN-instance.[PE1] ip vpn-instance vpn1[PE1-vpn-vpn1] route-distinguisher 2:1[PE1-vpn-vpn1] vpn-target 100:1 export-extcommunity[PE1-vpn-vpn1] vpn-target 100:1 import-extcommunityConfigure VLAN interface.
