The document discusses IP addressing and network design. It describes the functions of a hierarchical addressing scheme, including preventing duplication of addresses and supporting scalability. The use of VLSM and CIDR allows for more efficient use of address space by enabling route summarization. When creating an IP addressing scheme, the entire plan should be designed in advance to allow for growth and support physical layout, routing, and security. Factors like load balancing must also be considered in designing the routing strategy. The document also covers IPv6 implementations and transition methods from IPv4, such as dual stack and tunneling.

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Using IP Addressing in
the Network Design
Designing and Supporting Computer Networks – Chapter 6

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Objectives
 Describe the use of a hierarchical routing and
addressing scheme
 Create the IP address and naming scheme to support
growth and efficient routing protocol operation
 Describe IPv6 implementations and IPv6 to IPv4
interactions
 Implement IPv6 on a Cisco device

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Describe the Use of a Hierarchical
Routing and Addressing Scheme
Functions of a hierarchical addressing scheme:
 Prevent duplication of addresses
 Control access, monitor security and performance
 Support modular design and scalability

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Describe the Use of a Hierarchical
Routing and Addressing Scheme
 Poorly-planned IP addressing can result in
discontiguous subnets
 Routing protocols may display more than one summary
route to discontiguous subnets
 Manual configuration of routing protocols may be
required

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Describe the Use of a Hierarchical
Routing and Addressing Scheme
 VLSM provides more efficient use of IP address space
 VLSM enables routers to summarize routes on
classless boundaries

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Describe the Use of a Hierarchical
Routing and Addressing Scheme
 CIDR ignores classful boundaries
 CIDR enables supernets: VLSMs with shorter prefix
lengths than the defaults
• Summarization produces leaner routing tables

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Create the IP Address and Naming
Scheme
 Plan the entire
addressing scheme in
advance
 Allow for significant
growth
 Support the physical
layout, routing, and
security

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Create the IP Address and Naming
Scheme
 Define the addressing blocks scheme to support
summarization
 Document locations, VLAN or network type, and
number of hosts and networks

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Create the IP Address and Naming
Scheme
 Select the
appropriate routing
protocol to use in the
network
 Support classless
routing and VLSM
 Small and infrequent
updates to reduce
traffic
 Fast convergence

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Factors in designing the routing strategy:
 Load balancing
 Authentication
Create the IP Address and Naming
Scheme

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Create the IP Address and Naming
Scheme
 Determine when and how to summarize address space
for efficient routing

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Create the IP Address and Naming
Scheme
 Design an address scheme for an internetwork and
assign ranges for hosts, network devices, and the
router interface

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Create the IP Address and Naming
Scheme
 Determine an appropriate naming scheme
 Use codes and avoid names that easily identify
protected resources
 Maintain consistency
 Document the names

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Describe IPv6 Implementations and IPv6
to IPv4 Interactions
Enhancements available with IPv6:
 Mobility and security
 Simpler header
 Address formatting

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Describe IPv6 Implementations and IPv6
to IPv4 Interactions
Common transition
methods from IPv4 to
IPv6:
 Dual stack
 Tunneling
 Proxying and
translation

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Describe IPv6 Implementations and IPv6
to IPv4 Interactions
How to configure IPv6 on a Cisco device:
 Activate IPv6 forwarding
 Configure interfaces
 Configure name resolution

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RIPng for IPv6:
 The tag parameter in
interface configuration
mode
 The ipv6 rip name enable
command on directly-
connected routers
Describe IPv6 Implementations and IPv6
to IPv4 Interactions

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Summary
 Allocation of IP addresses must be planned and
documented.
 A properly-designed hierarchical IP addressing scheme
makes it easier to perform route summarization.
 A complex hierarchy of variable-sized networks can be
summarized at various points using a prefix address.
 The choice of routing protocol must support the VLSM
and summarization strategy.
 A good network naming scheme makes the network
easier to manage and easier to navigate.
 IPv6 addresses are written as a series of eight 16-bit
hexadecimal digits separated by colons.

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