A company is troubleshooting high latency on an AWS Direct Connect connection. The network team notices that the latency increases during peak hours. The connection uses a single virtual interface (VIF) with a 1 Gbps capacity. What is the MOST likely cause of the latency?
Congestion causes packet drops and increased latency.
Why this answer
The most likely cause of increased latency during peak hours is that the bandwidth limit of the virtual interface (VIF) is being exceeded. When traffic approaches or surpasses the 1 Gbps capacity, the router's egress queue begins to fill, causing packet buffering and queuing delay. This queuing delay directly manifests as higher round-trip time (RTT) and is a classic symptom of link saturation.
How to eliminate wrong answers
Option A is wrong because a VLAN ID mismatch would cause a complete loss of connectivity (no link state or BGP adjacency), not a gradual increase in latency during peak hours. Option C is wrong because jumbo frames (MTU 9001) reduce overhead and can improve throughput, but their absence does not cause latency to increase specifically during peak traffic; it would affect performance consistently regardless of load. Option D is wrong because BGP keepalive timers (default 60 seconds, hold time 180 seconds) control the speed of failure detection, not packet forwarding latency; setting them too high would delay route convergence but not increase per-packet delay.