Restrictions for VPLS Autodiscovery BGP Based
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Virtual Private LAN Service (VPLS) Autodiscovery supports only IPv4 addresses.
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VPLS Autodiscovery uses Forwarding Equivalence Class (FEC) 129 to convey endpoint information. Manually configured pseudowires use FEC 128.
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VPLS Autodiscovery is not supported with Layer 2 Tunnel Protocol Version 3 (L2TPv3).
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You can configure both autodiscovered and manually configured pseudowires in a single virtual forwarding instance (VFI). However, you cannot configure different pseudowires on the same peer PE device.
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After enabling VPLS Autodiscovery, if you manually configure a neighbor by using the neighbor command and both peers are in autodiscovery mode, each peer will receive discovery data for that VPLS. To prevent peers from receiving data for the VPLS domain, manually configure route target (RT) values.
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If you manually configure multiple pseudowires and target different IP addresses on the same PE device for each pseudowire, do not use the same virtual circuit (VC) ID to identify pseudowires that terminate at the same PE device.
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If you manually configure a neighbor on one PE device, you cannot configure the same pseudowire in the other direction by using autodiscovery on another PE device.
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Tunnel selection is not supported with autodiscovered neighbors.
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Up to 16 RTs are supported per VFI.
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The same RT is not allowed in multiple VFIs on the same PE device.
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The Border Gateway Protocol (BGP) autodiscovery process does not support dynamic, hierarchical VPLS. User-facing PE (U-PE) devices cannot discover network-facing PE (N-PE) devices, and N-PE devices cannot discover U-PE devices.
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Pseudowires for autodiscovered neighbors have split horizon enabled. (A split horizon is enabled by default on all interfaces. A split horizon blocks route information from being advertised by a device, irrespective of the interface from which the information originates.) Therefore, manually configure pseudowires for hierarchical VPLS. Ensure that U-PE devices do not participate in BGP autodiscovery for these pseudowires.
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Do not disable split horizon on autodiscovered neighbors. Split horizon is required with VPLS Autodiscovery.
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The provisioned peer address must be a /32 address bound to the peer’s Label Distribution Protocol (LDP) router ID.
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A peer PE device must be able to access the IP address that is used as the local LDP router ID. Even if the IP address is not used in the xconnect command on the peer PE device, the IP address must be reachable.