Cisco 思科 网络 技术 培训 文档 ppt6

Cisco 思科 网络 技术 培训 文档 ppt

Hierarcical AddressingLong Distance Path to 703 Path to 555 Path to nonlocal carrier Local Office Local Office Long Distance

Path to 1212

California

Virginia

Does a telephone switch in California know how to reach a specific line in Virginia? (1-703-555-1212)

Copyright ã 1997, Cisco Systems, Inc.

CID- Chap 7—#

Cisco 思科 网络 技术 培训 文档 ppt

Prefix Length Determined from Context32 bits Class A Prefix length = 8 Host

Class B

Prefix length = 16

Host

Class C

Prefix length = 24

Host

Variable-length prefixes are not a new invention– Prefix field identifies a network number – Host field identifies a device number

Copyright ã 1997, Cisco Systems, Inc.

CID- Chap 7—#

Cisco 思科 网络 技术 培训 文档 ppt

New Notation for Prefix Length “Classful” routers accept only a few prefix lengthsClass A 10.0.0.0/8

Class B

172.10.0.0/16

Class C

192.10.10.0/24

“Classless” routers accept any prefix length Prefix length is carried with an IP addressClass C 192.10.168.0/21

Copyright ã 1997, Cisco Systems, Inc.

CID- Chap 7—#

Cisco 思科 网络 技术 培训 文档 ppt

Subnetting Extends Prefix to the Right32 bits Assigned network ad dress Subnet ma sk Prefix

172. 255.

16. 255.Prefix length

0. 254 .

Host

0 0

255.255.254.0

11111111 . 11111111 .

1111111126 Subnets 172.16. 2.0 172.16. 4.0 172.16. 6.0

0 . 00000000510 Hosts Need 510 Hosts Need 510 Hosts Need 2 Hosts

Good address utilization Good address utilization Poor address utilization

RIP and IGRP require the same subnet mask on all interfaces

Copyright ã 1997, Cisco Systems, Inc.

CID- Chap 7—#

Cisco 思科 网络 技术 培训 文档 ppt

Classful Routing Protocols Do Not Advertise Prefix LengthRouter C: Where is network 131.108.0.0? 131.108.1.0/24 A advertises 131.108.0.0 A 192.168.1.0/16 C B advertises 131.108.0.0 B 131.108.2.0/24

Sunets must be contiguous when using classful routing b protocols

Copyright ã 1997, Cisco Systems, Inc.

CID- Chap 7—#

Cisco 思科 网络 技术 培训 文档 ppt

Classless Routing Protocols Allow Flexible Addressing131.108.1.0/24 131.108.2.0/24 131.108.13.4/30 131.108.13.8/30

131.108.1.0/24

131.108.2.0/24

A advertises 131.108.1.0/24 131.108.13.8/30

C

B advertises 131.108.2.0/24 131.108.13.4/30

A 192.168.1.0/16131.108.13.8/30

B131.108.13.4/30

Link-state and hybrid protocols understand VLS Discontiguous subnets do not present a connectivity issue for advanced routing protocols

Copyright ã 1997, Cisco Systems, Inc.

CID- Chap 7—#

Cisco 思科 网络 技术 培训 文档 ppt

VLSM Saves Subnets in the WAN131.108.13.4/30 255.255.255.252 131.108.13.8/30 255.255.255.252

131.108.15.0/24 255.255.255.0 131.108.13.12/30 255.255.255.252 131.108.13.16/30 255.255.255.252

Copyright ã 1997, Cisco Systems, Inc.

CID- Chap 7—#

Cisco 思科 网络 技术 培训 文档 ppt

Route Summarization (Aggregation)Prefix Prefix length Host

Subnetting extends prefix to the right

Prefix Prefix length

Host

Summarization collapses prefix to the left

Copyright ã 1997, Cisco Systems, Inc.

CID- Chap 7—#

Cisco 思科 网络 技术 培训 文档 ppt

Classless Routing and Prefix Routing192.108.168.0 I will just tell you about a summary route to 192.108.168.0/21. 192.108.169.0 192.108.170.0 192.108.171

.0 192.108.172.0 192.108.173.0 192.108.174.0 192.108.175.0

CIDR used by BGP4 Prefix routing used by EIGRP and OSPFCopyright ã 1997, Cisco Systems, Inc.CID- Chap 7—#

Cisco 思科 网络 技术 培训 文档 ppt

A Classless Routing Protocol Looks for the Longest Match202.222.5.33/32 202.222.5.32/27 202.222.5.0/24 202.222.0.0/16 0.0.0.0/0 host subnet network block of networks default

IP routers support host-specific routes, blocks of networks, default routesCopyright ã 1997, Cisco Systems, Inc.CID- Chap 7—#

Cisco 思科 网络 技术 培训 文档 ppt

Secondary Addressing172.16.1.1 172.16.2.1

172.16.1.2

172.16.2.2

Useful in switched networks– Router may relay packets, acting as a default gateway – Host may communicate directly, using ARP for learning

Copyright ã 1997, Cisco Systems, Inc.

CID- Chap 7—#

Cisco 思科 网络 技术 培训 文档 ppt

Host Address Assignment Static Dynamic– BOOTP – DHCP Address request

Address response

131.108.6.3 255.255.255.0

Copyright ã 1997, Cisco Systems, Inc.

CID- Chap 7—#

Cisco 思科 网络 技术 培训 文档 ppt

Name-to-Address TranslationDNS Table172.16.1.1 172.16.2.1 DNS/DHCP Server Client_1 172.16.1.2 Client_2 172.16.2.2 :: ::::::

DHCP TableNext avail.172.16.1.3 Client_1 172.16.1.2 Client_2 172.16.2.2

Cisco DNS/DHCP Manager– Manages domain names – SynchronizeIP addresses s – Supports secondary addressingCopyright ã 1997, Cisco Systems, Inc.CID- Chap 7—#

Cisco 思科 网络 技术 培训 文档 ppt

Private versus Registered AddressesPrivate network (for example, 10.0.0.0) Address translation gateway Public network (for example, Internet)

Three address blocks reserved for private networks– 10.0.0.0 (1 Class A) – 172.16.0.0 to 172.31.0.0 (16 Class B) – 192.168.0.0 to 192.168.255.0 (256 Class C)

Address translation must occur to reach the Internet

Copyright ã 1997, Cisco Systems, Inc.

CID- Chap 7—#

Cisco 思科 网络 技术 培训 文档 ppt

Network Address TranslationPrivate network (for example, 10.0.0.0) Public network (for example, Internet)

Cisco router provid …… 此处隐藏：3468字，全部文档内容请下载后查看。喜欢就下载吧 ……