CDCP Network Infrastructure and Connectivity 5

Question 1

What is the maximum transmission unit (MTU) typically required when using VXLAN encapsulation to avoid fragmentation of standard 1500-byte Ethernet frames?

Accepted Answer

9000 bytes

Answer

VXLAN adds 50 bytes of overhead; to carry a full 1500-byte payload without fragmentation, jumbo frames with an MTU of at least 1550 bytes are needed, and 9000-byte jumbo frames are the standard data center practice.

Question 2

In BGP-based data center fabrics, what is the role of the 'route reflector'?

Accepted Answer

It reduces full-mesh iBGP peering requirements by redistributing routes on behalf of peers

Answer

A BGP route reflector eliminates the need for every iBGP speaker to peer with every other, reducing O(n²) peering sessions to a hub-and-spoke model.

Question 3

Which technology allows a data center to present a single logical switch across multiple physical switches, simplifying topology and eliminating spanning tree?

Accepted Answer

VSS (Virtual Switching System) / MC-LAG

Answer

Multi-Chassis Link Aggregation (MC-LAG) technologies like VSS or vPC present multiple physical switches as a single logical device, enabling active-active uplinks without spanning tree loops.

Question 4

A colocation data center customer requests a cross-connect. What does a cross-connect provide?

Accepted Answer

A physical cable connection between two customer cages or a customer and a carrier

Answer

A cross-connect is a dedicated physical cable (copper or fiber) installed by the colocation facility to directly connect two parties within the same data center without traversing public networks.

Question 5

What is the primary purpose of an out-of-band (OOB) management network in a data center?

Accepted Answer

To provide device access for management and recovery independent of the production network

Answer

An OOB management network is physically separate from production traffic paths, allowing administrators to access, configure, or recover devices even when the in-band network is down.

CDCP - Certified Data Centre Professional Practice Test

CDCP - Certified Data Centre Professional Practice Test

CDCP Network Infrastructure and Connectivity 5