Endpoint SID representing the PE type, used to identify an IPv4VPN instance in the network:

Question

Options

• AEnd.DX4 SID
• BEnd.X SID
• CEnd.OP SID
• DEnDT4 SID

• A
  9% (2)
• B
  5% (1)
• C
  5% (1)
• D
  82% (18)

Explanation

End.DT4 (option D, written as "EnDT4" in the question - likely a typo) is correct because the "DT" stands for Decapsulate and Table lookup, where the SID maps directly to a specific IPv4 VRF (routing table) on the PE. When traffic arrives at the PE with this SID active, the router strips the SRv6 header and performs a lookup in the associated IPv4VPN instance, making it the SID that identifies an IPv4VPN instance in SRv6-based L3VPN.

• End.DX4 (A) is wrong because "DX" means Decapsulate and Cross-connect to a specific IPv4 next-hop adjacency, not a VRF table - used for single-homed CE scenarios where the egress neighbor is predetermined.
• End.X (B) is wrong because it represents a layer-3 cross-connect to a specific link/interface, used primarily for Traffic Engineering path steering, with no VPN table involvement.
• End.OP (C) is wrong because it is not a standard SRv6 PE SID type associated with VPN instance identification - it serves as a distractor.

Memory tip: Think DT = "Destination Table" - the T tells you it does a VRF table lookup. DX has an X for eXit to a neighbor, not a table. If the question mentions "VPN instance," look for the T.

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