• In designing a network it is necessary to categorize the
network depending on the number of devices that serve
• A small network provides services to 200 devices
• A medium network provides services 200-1000 devices
• a large network provides services to more than 1000
devices
•
Network designs require great knowledge and
experience to identify potential network expansions.
NETWORK REQUIREMENTS

STRUCTURED ENGINEERING
PRINCIPLES
• For a network designer, is indispensible have with a network design that
can comply with the challenges of connect a lot of areas in a enterprice.
To do it, exist rules of engineering that should be follow:
•
°Hierarchy: Make possible that the network can be divided in areas
more small and can be more easy to manage.
• °Modularity: Separate the network in functions that exist in this, to best
design.
•
°Resistance where the network should be prepared to resist and
work normal and abnormal conditions.
• °Flexibility, this capacity permit that the network can be update
or implement new sections or add news devices to the network.
•

HIERARCHICAL NETWORK DESIGN
• Hierarchical models apply to both LAN and WAN design.(LAN Local
Area Network and WAN Wide Area Network )
• A typical enterprise hierarchical LAN campus network design
includes the following three layers:
•
Access layer - Provides workgroup/user access to the network.
• Distribution layer - Provides policy-based connectivity and controls
the boundary between the access and core layers.
• Core layer - Provides fast transport between distribution switches
within the enterprise campus.
•

ACCESS LAYER
• The access layer grants end devices access to the network. In the
WAN environment, it may provide teleworkers or remote sites
access to the corporate network across WAN connections.
• Generally incorporates Layer 2 switches and access points
providing connectivity.
• The access layer serves a number of functions including:
• Layer 2 switching
• High availability
• Port security
• QoS classification and marking and trust boundaries
• Address Resolution Protocol (ARP) inspection
• VLAN Access Control List (VACL)
• Spanning tree
• Power over Ethernet (PoE) and auxiliary VLANs for VoIP

DISTRIBUTION LAYER
• the distribution layer is the boundary between the Layer
2 domains and the Layer 3 routed network.
•
simarizacion aggregation and towards the core layers
• aggregation LINKS WAN LAN
• Routing services between LANs and VLANs and
between routing domains
• filtering acl
• Redundancy and load balancing
• Broadcast domain control,

CORE LAYER
• The core layer is critical for interconnectivity between
distribution layer devices; for example, interconnecting the
distribution block to the WAN and Internet edge.
• Some considerations at the core layer are:
Providing high-speed switching (i.e., fast transport)
Providing reliability and fault tolerance
Scaling by using faster, and not more, equipment.
• Avoiding CPU-intensive packet manipulation caused by
security, inspection, quality of service
• The core layer must be capable of forwarding large amounts
of data quickly.

TWO-TIER COLLAPSED CORE DESIGN
• The three-tier hierarchical design maximizes
performance, network availability, and the ability to scale
the network design.
• A “collapsed core” is when the distribution layer and core
layer functions are implemented by a single device. The
primary motivation for the collapsed core design is
reducing network cost, while maintaining most of the
benefits of the three-tier hierarchical model.
•

MODULAR DESIGN
• A modular network design separates the network into
several modules functional network , and each of these
points to a place or a specific purpose in the network.
• The use of modules in the network design provides
flexibility and facilitates its implementation and
troubleshooting, allowing more control detailed security.

MODULAR DESIGN
• A modular approach to network design further divides the three-layer
hierarchical design, by pulling out specific blocks or modular areas. These basic
modules are connected together via the core of the network.
•
Access-distribution - Also called the distribution block
•
Services - This is a generic block used to identify services such as centralized
Lightweight Access Point Protocol (LWAPP) wireless controllers, unified
communications services, policy gateways.
•
• Data center - Originally called the server farm. This block is responsible for
managing and maintaining many data systems that are vital to modern business
operations.
• Enterprise Edge - Consists of the Internet Edge and the WAN Edge.
•

CISCO ENTERPRISE ARCHITECTURE
MODEL
• For have the need of Modularity in a network, Cisco
design the model of owner architecture, called
“modules”. This scheme permit major flexibility in the
network design and provided the resolution of
problems. Some modules or the architecture of Cisco:
•
Managerial campus
• Enterprise Edge
• End of the service provider
•

CISCO ENTERPRISE CAMPUS
• A campus network is a building or group of buildings
connected to a corporate network consisting of many
LAN.
•
Enterprise campus module consists of the following
submodules:
•
Access to the building
• Building Distribution
• Core campus
• Data center

CISCO ENTERPRISE ARCHITECTURE
MODEL
• The enterprise edge module provides connectivity for voice, video, and data services
outside the enterprise.
• The enterprise edge module consists of the following submodules:
• E-commerce networks and servers
• The e-commerce submodule enables enterprises to support e-commerce applications
through the Internet. It uses the high availability designs of the data center module.
• Internet connectivity and demilitarized zone (DMZ)
• The Internet submodule of the enterprise edge provides internal users with secure
connectivity to Internet services such as public servers, email, and DNS.
• Remote Access and VPN
• The VPN/remote access submodule of the enterprise edge provides remote-access
termination services, including authentication for remote users and sites.
• WAN
• The WAN submodule uses various WAN technologies for routing traffic between remote
sites and the central site.
•

SERVICE PROVIDER EDGE
• Enterprises use Service Providers (SPs) to link to other
sites. As shown in Figure 1, the SP edge module can
include:
• Internet Service Providers (ISPs)
• WAN services such as Frame Relay, ATM, and MAN
• Public Switched Telephone Network (PSTN) services

REMOTE FUNCTIONAL AREA
• This area is responsible for remote connectivity options and includes
several modules, it includes several modules,
• Enterprise Branch: The enterprise branch module includes remote
branches that allow employees to work at non-campus locations.
• The enterprise branch module allows enterprises to extend head-
office applications and services, such as security, Cisco Unified
Communications, and advanced application performance, to the
remote branches.
• Enterprise Teleworker:is responsible for providing connectivity for
workers who operate out of different geographically dispersed
locations.
• Enterprise Data Center: is a data center with all of the same
functional options as a campus data center, but exists at a remote
location

IT CHALLENGES
BYOD
• The networks are going to be a transportation system
only data composed of LAN devices connected to a
system that connects people, devices and information in
a converged network environment and with a variety of
means .

EMERGING ENTERPRISE
ARCHITECTURES
• To emerging network trends, new business network
architectures are necessary.
•
Cisco Borderless Network Architecture
• Collaboration Architecture
• Data Center/Virtualization Architecture

CISCO BORDERLESS NETWORKS
• The architecture Cisco Borderless Network it is a solution of
network that allows that the organizations and the persons
should connect in a sure way, with confidence and without
disadvantages to the managerial network in an environment
BYOD (Bring Your Own Device).
• The architecture Borderless Network admits an extremely
sure network and from high performance to that a wide variety
of devices can accede. Must be the sufficiently flexible thing in
order that it could climb and in order that it admits the future
growth into terms of the managerial expansion, included the
computer science BYOD, mobile and into the cloud.
•

CCNA 4 Hierarchical Network Design

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CCNA 4 Hierarchical Network Design