CS 6250 PROFESSIONAL NETWORKING
PREP QUESTIONS AND ACCURATE
ANSWERS GRADED A+
●● In SDN, forwarding is typically handled in the data plane, while
broader routing and policy logic belong to the control plane.
Answer: In SDN, forwarding is typically handled in the data plane,
while broader routing and policy logic belong to the control plane.
True
●● What is the core architectural idea behind SDN?
A) Move forwarding decisions entirely to end hosts
B) Separate the control plane from the data plane
C) Replace IP routing with Ethernet switching across the Internet
D) Centralize all packet forwarding in one physical device
Answer: What is the core architectural idea behind SDN?
B) Separate the control plane from the data plane
●● Which of the following was a major motivation for SDN?
A) Simplifying network-wide management and policy deployment
B) Eliminating the need for forwarding tables
C) Replacing routers with general-purpose servers at every hop
,D) Removing the need for transport-layer congestion control
Answer: Which of the following was a major motivation for SDN?
A) Simplifying network-wide management and policy deployment
●● What was the main reason that coupling of control and forwarding
was seen as a problem in traditional networks?
A) It made network-wide changes slow and error-prone because control
logic was embedded separately inside each
B) It prevented routers and switches from maintaining local forwarding
state
C) It required all traffic to follow a single centralized controller
D) It made it difficult for operators to express policy consistently across
devices from different vendors
Answer: What was the main reason that coupling of control and
forwarding was seen as a problem in traditional networks?
A) It made network-wide changes slow and error-prone because control
logic was embedded separately inside each
●● Which task best belongs to the control plane?
A) Looking up a forwarding-table entry for each arriving packet
B) Computing traffic-engineering policy for the network
C) Sending Ethernet frames out a selected interface
D) Performing per-hop packet-header validation at line rate
Answer: Which task best belongs to the control plane?
,B) Computing traffic-engineering policy for the network
●● Which statement best distinguishes forwarding from routing/control?
A) Forwarding is a local per-packet action, while routing/control
determines broader network behavior
B) Forwarding computes end-to-end paths, while routing applies local
table lookups
C) Forwarding and routing are interchangeable terms for the same
function
D) Forwarding is only used by switches, while routing/control is only
used by routers
Answer: Which statement best distinguishes forwarding from
routing/control?
A) Forwarding is a local per-packet action, while routing/control
determines broader network behavior
●● Why did network virtualization become an important driver for
SDN?
A) It reduced the need for addressing and routing between hosts
B) It created demand for flexible, centralized control over shared
infrastructure
C) It made transport-layer reliability unnecessary for cloud services
D) It eliminated the need for isolation between networks
, Answer: Why did network virtualization become an important driver for
SDN?
B) It created demand for flexible, centralized control over shared
infrastructure
●● Active networking influenced SDN mostly by introducing the idea
that:
A) Network devices should avoid any form of programmability
B) Programmability can lower barriers to innovation
C) Control logic should remain hard-coded inside vendor devices
D) End users should carry routing logic inside data packets in production
networks
Answer: Active networking influenced SDN mostly by introducing the
idea that:
B) Programmability can lower barriers to innovation
●● Which milestone helped make SDN practical rather than only
conceptual?
A) DNSSEC
B) OpenFlow and early controllers
C) NAT boxes
D) BitTorrent
Answer: Which milestone helped make SDN practical rather than only
conceptual?
PREP QUESTIONS AND ACCURATE
ANSWERS GRADED A+
●● In SDN, forwarding is typically handled in the data plane, while
broader routing and policy logic belong to the control plane.
Answer: In SDN, forwarding is typically handled in the data plane,
while broader routing and policy logic belong to the control plane.
True
●● What is the core architectural idea behind SDN?
A) Move forwarding decisions entirely to end hosts
B) Separate the control plane from the data plane
C) Replace IP routing with Ethernet switching across the Internet
D) Centralize all packet forwarding in one physical device
Answer: What is the core architectural idea behind SDN?
B) Separate the control plane from the data plane
●● Which of the following was a major motivation for SDN?
A) Simplifying network-wide management and policy deployment
B) Eliminating the need for forwarding tables
C) Replacing routers with general-purpose servers at every hop
,D) Removing the need for transport-layer congestion control
Answer: Which of the following was a major motivation for SDN?
A) Simplifying network-wide management and policy deployment
●● What was the main reason that coupling of control and forwarding
was seen as a problem in traditional networks?
A) It made network-wide changes slow and error-prone because control
logic was embedded separately inside each
B) It prevented routers and switches from maintaining local forwarding
state
C) It required all traffic to follow a single centralized controller
D) It made it difficult for operators to express policy consistently across
devices from different vendors
Answer: What was the main reason that coupling of control and
forwarding was seen as a problem in traditional networks?
A) It made network-wide changes slow and error-prone because control
logic was embedded separately inside each
●● Which task best belongs to the control plane?
A) Looking up a forwarding-table entry for each arriving packet
B) Computing traffic-engineering policy for the network
C) Sending Ethernet frames out a selected interface
D) Performing per-hop packet-header validation at line rate
Answer: Which task best belongs to the control plane?
,B) Computing traffic-engineering policy for the network
●● Which statement best distinguishes forwarding from routing/control?
A) Forwarding is a local per-packet action, while routing/control
determines broader network behavior
B) Forwarding computes end-to-end paths, while routing applies local
table lookups
C) Forwarding and routing are interchangeable terms for the same
function
D) Forwarding is only used by switches, while routing/control is only
used by routers
Answer: Which statement best distinguishes forwarding from
routing/control?
A) Forwarding is a local per-packet action, while routing/control
determines broader network behavior
●● Why did network virtualization become an important driver for
SDN?
A) It reduced the need for addressing and routing between hosts
B) It created demand for flexible, centralized control over shared
infrastructure
C) It made transport-layer reliability unnecessary for cloud services
D) It eliminated the need for isolation between networks
, Answer: Why did network virtualization become an important driver for
SDN?
B) It created demand for flexible, centralized control over shared
infrastructure
●● Active networking influenced SDN mostly by introducing the idea
that:
A) Network devices should avoid any form of programmability
B) Programmability can lower barriers to innovation
C) Control logic should remain hard-coded inside vendor devices
D) End users should carry routing logic inside data packets in production
networks
Answer: Active networking influenced SDN mostly by introducing the
idea that:
B) Programmability can lower barriers to innovation
●● Which milestone helped make SDN practical rather than only
conceptual?
A) DNSSEC
B) OpenFlow and early controllers
C) NAT boxes
D) BitTorrent
Answer: Which milestone helped make SDN practical rather than only
conceptual?
