You are deploying an IP fabric with an oversubscription ratio of 3:1. In this scenario, which two statements are correct? (Choose two.)

The oversubscription ratio in an IP fabric is the ratio of downstream bandwidth (server-facing) to upstream bandwidth (spine-facing). This ratio is determined by the port configuration on each leaf device. For example, a leaf with 48x10GbE downstream ports and 4x40GbE upstream ports has a ratio of (4810)/(440) = 3:1. The overall fabric ratio is the aggregate of all leaf devices. As long as all leaf devices added or removed have the same port configuration and ratio, the overall fabric oversubscription ratio remains constant. Adding or removing identical building blocks does not alter the fundamental ratio of the design.

A. The oversubscription ratio decreases when you add leaf devices.

Incorrect. Adding identically configured leaf devices adds both downstream and upstream capacity proportionally, keeping the ratio the same.

C. The oversubscription ratio increases when you remove leaf devices.

Incorrect. Removing identically configured leaf devices removes both downstream and upstream capacity proportionally, keeping the ratio the same.

1. Juniper Networks, "Data Center Fabric Architecture Design Guide" (2021). Section: "IP Fabric Design", Subsection: "Oversubscription". This guide explains that the oversubscription ratio is a key design parameter of the leaf switch and that scaling the fabric by adding or removing these leaf switches maintains the designed ratio.

2. Juniper Networks, "Juniper Apstra 4.2.0 User Guide" (2023). Section: "Reference > Design > Rack Types". The documentation on designing rack types inherently defines the oversubscription ratio per rack (leaf). When you instantiate more racks of the same type, the overall fabric ratio does not change.