Version 3.1 SP2 Reference Guide - Extreme Networks

Managing and Monitoring VPLS DomainsFigure 214: Fully meshed VPLS domainPEPEVPLS CorePEPECore Pseudo WiresIn a fully meshed VPLS domain, pseudo wires must be established between all VPLS peers across thecore. For each peer added to a VPLS domain, a PW is signaled that is used to carry traffic from the localLSR to the remote peer LSR. Flood traffic from the local service (broadcast, multicast, and unknownunicast packets) is replicated and forwarded across all PWs in the VPLS domain. Each peer receives onecopy of the packet for delivery to its locally attached service. As MAC learning occurs on PWs, unicastpackets to a known destination MAC address are forwarded to the peer over the PW from which theMAC address was learned.Hierarchical VPLS (H-VPLS)When MPLS is used at the edge of the network, a fully meshed VPLS domain becomes less practical,due to the number of PWs that must be configured between a large number of peers. A hierarchicalVPLS (H-VPLS) network can improve network scalability by reducing the number of PWs that need tobe configured between peers.In an H-VPLS domain, VPLS domains can be constructed hierarchically in a partial-mesh or hub-andspokeconfiguration. Within the context of H-VPLS, a spoke is a VPLS connection between two VPLSpeers. Typically, one spoke node provides connectivity to the customer VLAN or customer service whileits peer, a core node, provides repeater connectivity to other VPLS peers.H-VPLS introduces the concept of core and spoke PW types. In an interconnected fully meshed VPLSdomain, all of the PWs are of the type core. In an H-VPLS domain, PWs at the fully meshed core of thenetwork are of the type core, and PWs that connect peers at the edge of the network are of the typespoke.The forwarding rules for spoke and core pseudo wires are different. Flood traffic received on a corepseudo wire from another full-mesh core PE must not be transmitted over other core pseudo wires toother PEs. However, flood traffic received on a core pseudo wire is transmitted on all spoke pseudowires in the VPLS domain. Unlike core pseudo wires in a fully meshed VPLS, flood traffic received on aspoke pseudo wire must be transmitted on all other pseudo wires in the VPLS, including pseudo wiresto other core PEs.Figure 215 shows an example H-VPLS domain.288Ridgeline Reference Guide