A BGP route reflector in the network is taking longer than expected to coverage during large network changes. Troubleshooting shows that the router cannot handle all the TCP acknowledgements during…

The hold queue is an input buffer that stores incoming packets while the router's process level is busy. Increasing its size prevents TCP ACK packets from being tail-dropped during burst periods caused by large BGP route updates, allowing the router to catch up without losing acknowledgements that would trigger retransmissions and further instability. This directly addresses the symptom of the router being unable to handle all TCP acknowledgements during convergence.

Large buffers are used to accommodate larger-sized packets in memory, but the symptom is insufficient queuing capacity for incoming TCP ACK packets, not a buffer size issue for oversized frames.

Decreasing small buffer size would reduce the router's capacity to hold small packets such as TCP ACKs, which directly worsens the problem described.

BGP keepalive timers control session liveness detection intervals and have no effect on the router's ability to process incoming TCP acknowledgements during route updates.