A customer is migrating a branch site with a VMware SD-WAN Edge coexisting with the CE. The Edge will be connected to internet link directly while connecting to the CE via a Layer 3 LAN switch. MPLS…

Question

Options

• AUse BGP as the rout.ng protocol on UK Edge and flag its BGP neighbor to the Layer 3 LAN switch
• BUse BGP as the routing protocol on the Edge and filter prefixes from CE using Uplink Community
• CUse BGP as the routing protocol on the Edge and flag its HGP neighbor to PE as Uplink.
• DUse BGP as the routine, protocol on the Edge and flag its BGP neighbor to GE as Uplink.

• A
  12% (6)
• B
  4% (2)
• C
  78% (39)
• D
  6% (3)

Explanation

Option C is correct because in a VMware SD-WAN coexistence scenario, BGP is used between the Edge and the MPLS network, and flagging the BGP neighbor facing the Provider Edge (PE) as "Uplink" is the mechanism that tells the SD-WAN Edge to treat MPLS as the underlay path - this enables the Edge to automatically steer traffic to non-SD-WAN branches via MPLS underlay while preferring SD-WAN overlay for branches that have Edges.

Why the distractors are wrong:

• A flags the L3 LAN switch as the BGP neighbor, which is incorrect - the switch is a transit device, not the relevant BGP peer for MPLS route learning; the neighbor should be the PE-facing side.
• B uses "Uplink Community," which is a BGP community-tagging mechanism for a different use case and not the correct configuration parameter for designating a neighbor as an underlay path in SD-WAN coexistence.
• D flags the BGP neighbor toward the CE (not PE) as Uplink - the CE is the customer-side router; the PE is the MPLS provider edge, and flagging the neighbor toward the PE is what correctly signals the MPLS underlay relationship.

Memory tip: Think "PE = Provider = MPLS underlay." When the SD-WAN Edge needs to know which BGP neighbor leads to MPLS, flag the one pointing toward the Provider Edge (PE) as Uplink - the word "Uplink" literally means "this is my WAN/underlay path, not a LAN branch."

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