CCNA 200-301: Networking Fundamentals Q&A, Exams of Computer
Science
1.0 Network Fundamentals - ANSWER20%
1.1 Explain the role and function of network components - ANSWER• Router
basic functions
• Allow communication between IPv4 and IPv6 networks
• Allow communication between VLANs
• Separates broadcast domains
• Forward traffic based on layer 3 addressing
1.1.a Routers - ANSWER• Router basic functions
• Allow communication between IPv4 and IPv6 networks
• Allow communication between VLANs
• Separates broadcast domains
• Forward traffic based on layer 3 addressing
1.1.b Layer 2 and Layer 3 switches - ANSWER• Layer 2 Switch basic functions
• Allow communication between devices in the same IPv4 or IPv6 network.
,• Interfaces separate collision domains.
• Forwards traffic based on layer 2 addressing (MAC addressing)
• Builds a MAC address table also referred to as a CAM table
• Allows for the creation of broadcast domains via VLANs, but will not allow
different VLANs to pass traffic between them.
• Layer 3 Switch basic functions
• Combines functions of routers and switches into a single device
1.1.c Next-generation firewalls and IPS - ANSWER• NGFW basic functions
• This device is most common at the WAN edge of a network.
• Corporate traffic is inspected and response traffic is allowed to return, this
makes the FW a stateful FW.
• Other traffic will be denied from entering from the WAN to the LAN since it
was not previously inspected. The work around will be to permit the traffic
with an ACL typically.
1.1.d Access points - ANSWER• Wireless AP basic functions
• Provide connectivity to a network client without tethering via a cable.
• This device does not route traffic, so your best comparison is with a switch.
• These devices will use MIMO to get around the fact that wireless networks
are half duplex
1.1.e Controllers - ANSWER• Wireless Controllers basic functions
,• Wireless deployments are either autonomous or lightweight. Autonomous
AP are fully configurable via its command line, and lightweight access points
are not.
• LAP are instead configured via a centralized management device known as
a controller.
• LAP download their configurations from the WLC.
• The WLC does not have a radio for communication but is instead a wired
device.
1.1.f Endpoints - ANSWER• Endpoints
• Devices used to access a network such as PCs, tablets, and phones.
1.1.g Servers - ANSWER• Servers
• Devices that house information and provide access to resources.
1.1.h PoE - ANSWERa technology that makes it possible to transmit both data
and electrical energy via the same twisted-pair Ethernet cable
1.2 Describe characteristics of network topology architectures - ANSWER•
The most traditional of designs
• Consists of 3 layers a Core, a Distribution, and an Access
• The core is a high speed backbone that provides connection to the WAN
edge, server farm, and distribution layer.
• The distribution layer aggregates access layer switches and connects to the
core.
• The access layer connects endpoints (end users) and is aggregated by the
distribution layer switches.
, 1.2.a Two-tier - ANSWER• The Core and Distribution layers collapse into one
another, but the Access layer is still distinct.
• Consists of 2 layers Core/Distribution, and a separate Access.
• The core/distribution is a high-speed backbone that provides connection to
the WAN edge and server farm. It also aggregates access layer switches.
• This implementation is usually used for smaller networks when compared
to the 3 3-tier design.
1.2.b Three-tier - ANSWER• The most traditional of designs
• Consists of 3 layers a Core, a Distribution, and an Access
• The core is a high speed backbone that provides connection to the WAN
edge, server farm, and distribution layer.
• The distribution layer aggregates access layer switches and connects to the
core.
• The access layer connects endpoints (end users) and is aggregated by the
distribution layer switches.
1.2.c Spine-leaf - ANSWER• In this two-tier Clos architecture (named after
Charles Clos in 1958), every lower-tier switch (leaf layer) is connected to each
of the top-tier switches (spine layer) in a full-mesh topology.
• The leaf layer consists of access switches that connect to devices such as
servers. The spine layer is the backbone of the network and is responsible for
interconnecting all leaf switches.
• The path between the leaf and spine is randomly chosen so that the traffic
load is evenly distributed among the top-tier switches. If one of the top tier
switches were to fail, it would only slightly degrade performance throughout
the data center.
Science
1.0 Network Fundamentals - ANSWER20%
1.1 Explain the role and function of network components - ANSWER• Router
basic functions
• Allow communication between IPv4 and IPv6 networks
• Allow communication between VLANs
• Separates broadcast domains
• Forward traffic based on layer 3 addressing
1.1.a Routers - ANSWER• Router basic functions
• Allow communication between IPv4 and IPv6 networks
• Allow communication between VLANs
• Separates broadcast domains
• Forward traffic based on layer 3 addressing
1.1.b Layer 2 and Layer 3 switches - ANSWER• Layer 2 Switch basic functions
• Allow communication between devices in the same IPv4 or IPv6 network.
,• Interfaces separate collision domains.
• Forwards traffic based on layer 2 addressing (MAC addressing)
• Builds a MAC address table also referred to as a CAM table
• Allows for the creation of broadcast domains via VLANs, but will not allow
different VLANs to pass traffic between them.
• Layer 3 Switch basic functions
• Combines functions of routers and switches into a single device
1.1.c Next-generation firewalls and IPS - ANSWER• NGFW basic functions
• This device is most common at the WAN edge of a network.
• Corporate traffic is inspected and response traffic is allowed to return, this
makes the FW a stateful FW.
• Other traffic will be denied from entering from the WAN to the LAN since it
was not previously inspected. The work around will be to permit the traffic
with an ACL typically.
1.1.d Access points - ANSWER• Wireless AP basic functions
• Provide connectivity to a network client without tethering via a cable.
• This device does not route traffic, so your best comparison is with a switch.
• These devices will use MIMO to get around the fact that wireless networks
are half duplex
1.1.e Controllers - ANSWER• Wireless Controllers basic functions
,• Wireless deployments are either autonomous or lightweight. Autonomous
AP are fully configurable via its command line, and lightweight access points
are not.
• LAP are instead configured via a centralized management device known as
a controller.
• LAP download their configurations from the WLC.
• The WLC does not have a radio for communication but is instead a wired
device.
1.1.f Endpoints - ANSWER• Endpoints
• Devices used to access a network such as PCs, tablets, and phones.
1.1.g Servers - ANSWER• Servers
• Devices that house information and provide access to resources.
1.1.h PoE - ANSWERa technology that makes it possible to transmit both data
and electrical energy via the same twisted-pair Ethernet cable
1.2 Describe characteristics of network topology architectures - ANSWER•
The most traditional of designs
• Consists of 3 layers a Core, a Distribution, and an Access
• The core is a high speed backbone that provides connection to the WAN
edge, server farm, and distribution layer.
• The distribution layer aggregates access layer switches and connects to the
core.
• The access layer connects endpoints (end users) and is aggregated by the
distribution layer switches.
, 1.2.a Two-tier - ANSWER• The Core and Distribution layers collapse into one
another, but the Access layer is still distinct.
• Consists of 2 layers Core/Distribution, and a separate Access.
• The core/distribution is a high-speed backbone that provides connection to
the WAN edge and server farm. It also aggregates access layer switches.
• This implementation is usually used for smaller networks when compared
to the 3 3-tier design.
1.2.b Three-tier - ANSWER• The most traditional of designs
• Consists of 3 layers a Core, a Distribution, and an Access
• The core is a high speed backbone that provides connection to the WAN
edge, server farm, and distribution layer.
• The distribution layer aggregates access layer switches and connects to the
core.
• The access layer connects endpoints (end users) and is aggregated by the
distribution layer switches.
1.2.c Spine-leaf - ANSWER• In this two-tier Clos architecture (named after
Charles Clos in 1958), every lower-tier switch (leaf layer) is connected to each
of the top-tier switches (spine layer) in a full-mesh topology.
• The leaf layer consists of access switches that connect to devices such as
servers. The spine layer is the backbone of the network and is responsible for
interconnecting all leaf switches.
• The path between the leaf and spine is randomly chosen so that the traffic
load is evenly distributed among the top-tier switches. If one of the top tier
switches were to fail, it would only slightly degrade performance throughout
the data center.
