文档介绍：路由信息协议 RIP
深圳职业技术学院计算机系网络专业
教学目标( Objectives )
1. 动态路由(Dynamic Routing)
2. 距离向量路由协议( Distance Vector Protocol)
( Administrative Distance and Metric)
4. 路由信息协议(RIP)
5. RIP配置(Configing RIP)
6. 路由环路( Routing Loops )
路由器怎样传递数据包 (How routers route packets from source to destination )
(remove the data link layer address)
(refer to the routing table)
(encapsulating a new frame)
(forwarding the packet)
动态路由(Dynamic Routing)
适应拓扑结构的变化
Adapting to topology change
动态路由协议分类 (Classes of Dynamic Routing Protocols)
Distance Vector:rip
距离向量
Hybrid Routing:eigrp
混合路由
Link State:ospf
链路状态
C
B
A
D
C
D
B
A
如何衡量路径的好坏呢?
管理距离(Administrative Distance)
IGRP Administrative
Distance=100
Router D
Router B
Router A
Router C
RIP Administrative
Distance=120
E
I need to send a packet work E. Both router B and C will get it there. Which route is best?
管理距离用于衡量其作为路由信息源的可信度。
A measure of the reliability of the route
管理距离越低,路由选择协议的可信度越高。
A lower value for the administrative distance indicates the more reliable route
默认管理距离 (Default Administrative Distance)
路由选择协议
Routing Protocol
管理距离
AD
直连的接口(connected)
0
static
1
EIGRP
90
IGRP
100
OSPF
110
RIP
120
度量值( Metric )
度量值越小,路径就越好。
A lower value for the metric indicates the more reliable route
度量因素(factors for metric):
带宽(Bandwidth)
延迟(Delay)
负载(Load)
可靠性(Reliability)
跳数(Hop Count)
用度量值选择最佳路径 (Selecting Best Route with Metrics)
56
T1
56
T1
B
A
Hop count
跳数
RIP
IGRP
Bandwidth
Delay
Load
Reliability
MTU
Case Study 1
1. [120/2]
2. [120/2]
3. [100/35556]
4. [90/1288]
5. [90/19999]
根据管理距离和度量值对路径由好到坏排序:
4
5
3
2
1