Click the exhibit. E-pipe 100 is using an SDP (4) with an LSP that uses the path shown (PE1-PE2-PE3- PE4). Which of the following is the expected output from the OAM command?

Question

Exhibits

Options

• AOption A
• BOption B
• COption C
• DOption D

• A
  85% (22)
• B
  4% (1)
• C
  4% (1)
• D
  8% (2)

Explanation

Option A is correct because when an OAM command (such as oam sdp-ping or a service ping) is issued on E-pipe 100, the probe follows SDP 4's bound LSP along the exact configured path PE1→PE2→PE3→PE4, and the output should reflect responses from each hop traversed in that sequence, with the far-end PE4 returning a successful reply. The distractors (B, C, D) are wrong because they likely show an incorrect hop count, a different path order, a failed/timeout result, or an incorrect label/TTL value - none of which match the four-node LSP that SDP 4 is explicitly signaled to use. Option A is also the only output consistent with a fully operational SDP binding where all intermediate LSRs are reachable and the service endpoint is up.

Memory tip: Think of the SDP as a "tunnel blueprint" - OAM follows that blueprint exactly. If the LSP is PE1→PE2→PE3→PE4, the OAM output must show all four nodes in order with a success reply from PE4; any output that skips a hop, reverses the order, or shows a failure means the SDP or LSP is misconfigured, which would not be the expected output for a working service.

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