You are designing a large-scale DMVPN network with more than 500 spokes using EIGRP as...

In DMVPN designs with many spokes, spokes may fail to receive periodic keepalives or routing updates if queues overflow during congestion, causing holding timers to expire and tunnels to flap. Increasing the hold queue size on the tunnel interface of the spoke routers allows them to buffer control plane packets during congestion and avoid premature tunnel teardown.

Why other options are incorrect:

A, C, E: Physical interface queues do not directly affect tunnel protocol timers.

D: QoS may help prioritize control plane traffic but doesn't address queue depth directly, which is the root cause of the issue.

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