nerdexam
Fortinet

FCSS_NST_SE-7.4 · Question #80

Refer to the exhibit, which shows the output of a BGP debug command. Why has the local router at 172.16.23.58 been unable to establish adjacency with its only neighbor?

The correct answer is C. The local router has not received a SYN/ACK packet from the neighbor. In BGP's Connect state the router has sent the initial TCP SYN but hasn't received the SYN/ACK from its peer, so the TCP handshake never completes and adjacency can't form.

Routing and Policy Troubleshooting

Question

Refer to the exhibit, which shows the output of a BGP debug command. Why has the local router at 172.16.23.58 been unable to establish adjacency with its only neighbor?

Exhibit

FCSS_NST_SE-7.4 question #80 exhibit

Options

  • AThe local router has not received a keepalive message from the neighbor.
  • BThere is no active route to the BGP neighbor.
  • CThe local router has not received a SYN/ACK packet from the neighbor.
  • DThe local router has not received an OPEN message from the neighbor.

How the community answered

(29 responses)
  • A
    3% (1)
  • B
    10% (3)
  • C
    83% (24)
  • D
    3% (1)

Explanation

In BGP's Connect state the router has sent the initial TCP SYN but hasn't received the SYN/ACK from its peer, so the TCP handshake never completes and adjacency can't form.

Topics

#BGP adjacency#TCP three-way handshake#BGP debug#SYN/ACK

Community Discussion

No community discussion yet for this question.

Full FCSS_NST_SE-7.4 Practice