Using IP Addressing in the Network Design

Transcription

1 Using IP Addressing in the Network Design Designing and Supporting Computer Networks Chapter 6 Version Cisco Systems, Inc. All rights reserved. Cisco Public 1

2 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 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 2

3 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 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 3

4 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 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 4

5 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 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 5

6 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 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 6

7 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 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 7

8 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 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 8

9 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 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 9

10 Create the IP Address and Naming Scheme Factors in designing the routing strategy: Load balancing Authentication 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 10

11 Create the IP Address and Naming Scheme Determine when and how to summarize address space for efficient routing 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 11

12 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 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 12

13 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 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 13

14 Describe IPv6 Implementations and IPv6 to IPv4 Interactions Enhancements available with IPv6: Mobility and security Simpler header Address formatting 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 14

15 Describe IPv6 Implementations and IPv6 to IPv4 Interactions Common transition methods from IPv4 to IPv6: Dual stack Tunneling Proxying and translation 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 15

16 Describe IPv6 Implementations and IPv6 to IPv4 Interactions How to configure IPv6 on a Cisco device: Activate IPv6 forwarding Configure interfaces Configure name resolution 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 16

17 Describe IPv6 Implementations and IPv6 to IPv4 Interactions RIPng for IPv6: The tag parameter in interface configuration mode The ipv6 rip name enable command on directlyconnected routers 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 17

18 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 Cisco Systems, Inc. All rights reserved. Cisco Public 18

19 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 19