A BGP route reflector in the network is talking longer than expected to converge during network changes. Troubleshooting has shown that the router cannot handle all the TCP acknowledgements during rou

Question

Options

• AIncrease the size of the large buffers
• BDecrease the size of the small buffers
• CIncrease the keepalive timers for each BGP neighbor
• DIncrease the size of the hold queue

• A
  3% (2)
• B
  3% (2)
• C
  12% (7)
• D
  81% (48)

Explanation

Increasing the hold queue size directly addresses the bottleneck: the hold queue is an inbound buffer that stores incoming packets (including TCP ACKs) while the CPU processes them - when it's too small, packets are dropped before the CPU can handle them, stalling BGP convergence. Large buffers (A) affect memory allocation for bigger packets but don't control how many packets can queue for CPU processing, so they miss the root cause. Decreasing small buffers (B) would actually worsen performance by reducing capacity for the small TCP ACK packets that are already overwhelming the router. Increasing keepalive timers (C) only affects BGP session maintenance intervals, not the router's ability to process the flood of TCP acknowledgements during a route update event.

Memory tip: Think of the hold queue as a waiting room for incoming packets - if it's too small, TCP ACKs get turned away (dropped) before the CPU can serve them. "Hold" = hold packets in line, so when convergence is slow due to dropped ACKs, hold the line longer by increasing the hold queue.

No community discussion yet for this question.