1.路由器的工作原理
1.1 路由概述
路由：从源主机到目标主机的转发过程
路由（routing）是指分组从源到目的地时，决定端到端路径的网络范围的进程。路由工作在OSI参考模型第三层——网络层的数据包转发设备。路由器通过转发数据包来实现网络互连。虽然路由器可以支持多种协议（如TCP/IP、IPX/SPX、AppleTalk等协议），但是在我国绝大多数路由器运行TCP/IP协议。路由器通常连接两个或多个由IP子网或点到点协议标识的逻辑端口，至少拥有1个物理端口。路由器根据收到数据包中的网络层地址以及路由器内部维护的路由表决定输出端口以及下一跳地址，并且重写链路层数据包头实现转发数据包。路由器通过动态维护路由表来反映当前的网络拓扑，并通过网络上其他路由器交换路由和链路信息来维护路由表。
1.2 路由器工作原理
路由器根据路由表转发数据
作用在OSI模型的第三层，提供了路由与转发两种重要机制
注：路由器工作在网络层
路由器隔离广播域，交换机隔离冲突域
路由器的每一个端口就是一个网络
路由表是路由器转发数据的唯一依据
路由表中有路由才会转发，没有路由会丢弃
路由：路由器控制层面的工作，决定数据包从来源端到目的端所经过的路由路径（host到host的最佳传输路径）
转发：路由器数据层面的工作，将路由器输入端的数据包移送至适当的路由器输出端（在路由器内部进行）
路由器是一种具有多个输入端口和多个输出端口的专用计算机，其任务是转发分组。
也就是说，将路由器某个输入端口收到的分组，按照分组要去的目的地，把该分组从路由器的某个合适的输出端口转发给下一跳的路由器。
下一跳的路由器也按照这种方法处理分组，直到该分组到达终点为止。
2.路由表的形成
2.1 什么是路由表
路由表（routing table）或称路由择域信息库（RIB, Routing Information Base），是一个存储在路由器或者联网计算机中的电子表格（文件）或类数据库。路由表存储着指向特定网络地址的路径（在有些情况下，还记录有路径的路由度量值）。路由表中含有网络周边的拓扑信息。路由表建立的主要目标是为了实现路由协议和静态路由选择。
路由表定义：路由器中维护路由条目的集合
路由表作用：路由器根据路由表做路径选择
2.2 路由表的分类
1.直连网段——自动形成，配置IP地址，端口UP状态，形成直连路由
2.非直连网段分为：①管理手动配置——静态路由
②自动学习——动态路由
路由表的形成：1.直连路由——本地接口配置IP地址和子网掩码，接口开启后形成的路由
2.非直连路由——不是本地接口配置IP地址和子网掩码，接口开启后形成的路由
2.3 路由表的构成
目的网络地址（Dest）
掩码（Mask）
下一跳地址（GW）
发送的物理端口（interface）
路由信息的来源（Owner）
路由优先级（pri）
度量值（metric）
注：对于非直连路由的学习，有两种方式，一种管理员手动添加——静态路由，还有一种是路由通过路由协议自动学习的方式，这种方式叫动态路由。
3.静态路由和默认路由
3.1 静态路由
静态路由：由管理员手工配置的，是单向的，缺乏灵活性
静态路由特点：管理员添加的路由传输方向是单向的
静态路由优点：配置灵活，管理员手工配置，节省链路开销
静态路由缺点：当拓扑发生改变时，需要管理员去每台路由器上修改路由配置
建议五条以内的非直连路由用静态路由协议，五条以上的用动态路由协议
静态路由协议只能小规模的企业网络，大型企业网络用的是动态路由协议
默认路由是静态路由的一种特殊形式，它属于静态路由的一种，使用它是有条件的，只能在末梢/末节网络中使用
下一跳：指的是路由数据转发方向的下一台路由器
路由指明方向有两种方法：
方法一：指明该条路由本地路由器出接口
方法二：指明该条路由下一跳入接口IP
静态路由命令：[ ]ip route-static 目的网段 子网掩码/掩码长度 下一跳入接口IP
在进行静态路由配置的时候，需要知道：
①总共有几条路由 ②本地路由器缺少几条路由 ③路由转发的方向
<Huawei>un
<Huawei>undo te
<Huawei>undo terminal mo
<Huawei>undo terminal monitor
Info: Current terminal monitor is off.
<Huawei>sys
<Huawei>system-view
Enter system view, return user view with Ctrl+Z.
[Huawei]sysn
[Huawei]sysname r1
[r1]us
[r1]user-in
[r1]user-interface c
[r1]user-interface co
[r1]user-interface console 0
[r1-ui-console0]id
[r1-ui-console0]idle-timeout 0 0
[r1-ui-console0]q
[r1]int g0/0/1
[r1-GigabitEthernet0/0/1]ip ad
[r1-GigabitEthernet0/0/1]ip address 10.1.1.1
^
Error:Incomplete command found at '^' position.
[r1-GigabitEthernet0/0/1]ip ad
[r1-GigabitEthernet0/0/1]ip address 10.1.1.1 24
[r1-GigabitEthernet0/0/1]un
[r1-GigabitEthernet0/0/1]undo sh
[r1-GigabitEthernet0/0/1]undo shutdown
Info: Interface GigabitEthernet0/0/1 is not shutdown.
[r1-GigabitEthernet0/0/1]int g0/0/0
[r1-GigabitEthernet0/0/0]ip ad
[r1-GigabitEthernet0/0/0]ip address 10.1.2.1 24
[r1-GigabitEthernet0/0/0]un
[r1-GigabitEthernet0/0/0]undo sh
[r1-GigabitEthernet0/0/0]undo shutdown
Info: Interface GigabitEthernet0/0/0 is not shutdown.
[r1-GigabitEthernet0/0/0]q
[r1]ping 10.1.1.10
PING 10.1.1.10: 56 data bytes, press CTRL_C to break
Reply from 10.1.1.10: bytes=56 Sequence=1 ttl=128 time=60 ms
Reply from 10.1.1.10: bytes=56 Sequence=2 ttl=128 time=40 ms
Reply from 10.1.1.10: bytes=56 Sequence=3 ttl=128 time=50 ms
Reply from 10.1.1.10: bytes=56 Sequence=4 ttl=128 time=40 ms
Reply from 10.1.1.10: bytes=56 Sequence=5 ttl=128 time=30 ms
--- 10.1.1.10 ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
round-trip min/avg/max = 30/44/60 ms
[r1]dis
[r1]display ip ro
[r1]display ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 6 Routes : 6
Destination/Mask Proto Pre Cost Flags NextHop Interface
10.1.1.0/24 Direct 0 0 D 10.1.1.1 GigabitEthernet
0/0/1
10.1.1.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
10.1.2.0/24 Direct 0 0 D 10.1.2.1 GigabitEthernet
0/0/0
10.1.2.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
[r1]rou
[r1]ip ro
[r1]ip route-st
[r1]ip route-static 10.1.3.0 24 10.1.2.2
[r1]ip route-static 10.1.4.0 24 10.1.2.2
[r1]dis
[r1]display ip ro
[r1]display ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 8 Routes : 8
Destination/Mask Proto Pre Cost Flags NextHop Interface
10.1.1.0/24 Direct 0 0 D 10.1.1.1 GigabitEthernet
0/0/1
10.1.1.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
10.1.2.0/24 Direct 0 0 D 10.1.2.1 GigabitEthernet
0/0/0
10.1.2.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
10.1.3.0/24 Static 60 0 RD 10.1.2.2 GigabitEthernet
0/0/0
10.1.4.0/24 Static 60 0 RD 10.1.2.2 GigabitEthernet
0/0/0
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
[r1]<Huawei>un
<Huawei>undo te
<Huawei>undo terminal mo
<Huawei>undo terminal monitor
Info: Current terminal monitor is off.
<Huawei>sys
<Huawei>system-view
Enter system view, return user view with Ctrl+Z.
[Huawei]
[Huawei]sysn
[Huawei]sysname r2
[r2]us
[r2]user-in
[r2]user-interface co
[r2]user-interface console 0
[r2-ui-console0]id
[r2-ui-console0]idle-timeout 0 0
[r2-ui-console0]q
[r2]int g0/0/0
[r2-GigabitEthernet0/0/0]ip ad
[r2-GigabitEthernet0/0/0]ip address 10.1.2.2 24
[r2-GigabitEthernet0/0/0]un
[r2-GigabitEthernet0/0/0]undo sh
[r2-GigabitEthernet0/0/0]undo shutdown
Info: Interface GigabitEthernet0/0/0 is not shutdown.
[r2-GigabitEthernet0/0/0]int g0/0/1
[r2-GigabitEthernet0/0/1]ip ad
[r2-GigabitEthernet0/0/1]ip address 10.1.3.2 24
[r2-GigabitEthernet0/0/1]un
[r2-GigabitEthernet0/0/1]undo sh
[r2-GigabitEthernet0/0/1]undo shutdown
Info: Interface GigabitEthernet0/0/1 is not shutdown.
[r2-GigabitEthernet0/0/1]q
[r2]ping 10.1.2.1
PING 10.1.2.1: 56 data bytes, press CTRL_C to break
Reply from 10.1.2.1: bytes=56 Sequence=1 ttl=255 time=60 ms
Reply from 10.1.2.1: bytes=56 Sequence=2 ttl=255 time=20 ms
Reply from 10.1.2.1: bytes=56 Sequence=3 ttl=255 time=50 ms
Reply from 10.1.2.1: bytes=56 Sequence=4 ttl=255 time=50 ms
Reply from 10.1.2.1: bytes=56 Sequence=5 ttl=255 time=30 ms
--- 10.1.2.1 ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
round-trip min/avg/max = 20/42/60 ms
[r2]ping 10.1.3.1
PING 10.1.3.1: 56 data bytes, press CTRL_C to break
Request time out
Request time out
Request time out
Request time out
Request time out
--- 10.1.3.1 ping statistics ---
5 packet(s) transmitted
0 packet(s) received
100.00% packet loss
[r2]
[r2]ping 10.1.3.3
PING 10.1.3.3: 56 data bytes, press CTRL_C to break
Reply from 10.1.3.3: bytes=56 Sequence=1 ttl=255 time=60 ms
Reply from 10.1.3.3: bytes=56 Sequence=2 ttl=255 time=50 ms
Reply from 10.1.3.3: bytes=56 Sequence=3 ttl=255 time=50 ms
Reply from 10.1.3.3: bytes=56 Sequence=4 ttl=255 time=30 ms
Reply from 10.1.3.3: bytes=56 Sequence=5 ttl=255 time=50 ms
--- 10.1.3.3 ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
round-trip min/avg/max = 30/48/60 ms
[r2]dis
[r2]display ip ro
[r2]display ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 6 Routes : 6
Destination/Mask Proto Pre Cost Flags NextHop Interface
10.1.2.0/24 Direct 0 0 D 10.1.2.2 GigabitEthernet
0/0/0
10.1.2.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
10.1.3.0/24 Direct 0 0 D 10.1.3.2 GigabitEthernet
0/0/1
10.1.3.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
[r2]ip ro
[r2]ip route-st
[r2]ip route-static 10.1.1.0 24 10.1.2.1
[r2]ip ro
[r2]ip route-syt
[r2]ip route-st
[r2]ip route-static 10.1.4.0 24 10.1.3.3
[r2]dis
[r2]display ip ro
[r2]display ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 8 Routes : 8
Destination/Mask Proto Pre Cost Flags NextHop Interface
10.1.1.0/24 Static 60 0 RD 10.1.2.1 GigabitEthernet
0/0/0
10.1.2.0/24 Direct 0 0 D 10.1.2.2 GigabitEthernet
0/0/0
10.1.2.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
10.1.3.0/24 Direct 0 0 D 10.1.3.2 GigabitEthernet
0/0/1
10.1.3.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
10.1.4.0/24 Static 60 0 RD 10.1.3.3 GigabitEthernet
0/0/1
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
[r2]<Huawei>un
<Huawei>undo te
<Huawei>undo terminal mo
<Huawei>undo terminal monitor
Info: Current terminal monitor is off.
<Huawei>sys
<Huawei>system-view
Enter system view, return user view with Ctrl+Z.
[Huawei]sysn
[Huawei]sysname r3
[r3]us
[r3]user-in
[r3]user-interface co
[r3]user-interface console 0
[r3-ui-console0]id
[r3-ui-console0]idle-timeout 0 0
[r3-ui-console0]q
[r3]int g0/0/0
[r3-GigabitEthernet0/0/0]ip ad
[r3-GigabitEthernet0/0/0]ip address 10.1.3.3 24
[r3-GigabitEthernet0/0/0]uh
[r3-GigabitEthernet0/0/0]un
[r3-GigabitEthernet0/0/0]undo sh
[r3-GigabitEthernet0/0/0]undo shutdown
Info: Interface GigabitEthernet0/0/0 is not shutdown.
[r3-GigabitEthernet0/0/0]int g0/0/1
[r3-GigabitEthernet0/0/1]ip ad
[r3-GigabitEthernet0/0/1]ip address 10.1.4.3 24
[r3-GigabitEthernet0/0/1]un
[r3-GigabitEthernet0/0/1]undo sh
[r3-GigabitEthernet0/0/1]undo shutdown
Info: Interface GigabitEthernet0/0/1 is not shutdown.
[r3-GigabitEthernet0/0/1]
[r3-GigabitEthernet0/0/1]q
[r3]ping 10.1.4.10
PING 10.1.4.10: 56 data bytes, press CTRL_C to break
Reply from 10.1.4.10: bytes=56 Sequence=1 ttl=128 time=60 ms
Reply from 10.1.4.10: bytes=56 Sequence=2 ttl=128 time=40 ms
Reply from 10.1.4.10: bytes=56 Sequence=3 ttl=128 time=30 ms
Reply from 10.1.4.10: bytes=56 Sequence=4 ttl=128 time=10 ms
Reply from 10.1.4.10: bytes=56 Sequence=5 ttl=128 time=50 ms
--- 10.1.4.10 ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
round-trip min/avg/max = 10/38/60 ms
[r3]dis
[r3]display ip
[r3]display ip-ro
[r3]display ip ro
[r3]display ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 6 Routes : 6
Destination/Mask Proto Pre Cost Flags NextHop Interface
10.1.3.0/24 Direct 0 0 D 10.1.3.3 GigabitEthernet
0/0/0
10.1.3.3/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
10.1.4.0/24 Direct 0 0 D 10.1.4.3 GigabitEthernet
0/0/1
10.1.4.3/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
[r3]ip ro
[r3]ip route-st
[r3]ip route-static 10.1.1.0 24 10.1.3.2
[r3]ip ro
[r3]ip route-st
[r3]ip route-static 10.1.2.0 24 10.1.3.2
[r3]dis
[r3]display ip ro
[r3]display ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 8 Routes : 8
Destination/Mask Proto Pre Cost Flags NextHop Interface
10.1.1.0/24 Static 60 0 RD 10.1.3.2 GigabitEthernet
0/0/0
10.1.2.0/24 Static 60 0 RD 10.1.3.2 GigabitEthernet
0/0/0
10.1.3.0/24 Direct 0 0 D 10.1.3.3 GigabitEthernet
0/0/0
10.1.3.3/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
10.1.4.0/24 Direct 0 0 D 10.1.4.3 GigabitEthernet
0/0/1
10.1.4.3/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
[r3]选取最优路由时的标准：
1.子网掩码长度最长的最优先匹配
2.选取路由协议中优先级最小的最优先匹配
DIRECT:0
OSPF:10
IS-IS:15
STATIC:60
RIP:100
OSPF ASE:150
OSPF NSSA:150
IBGP:256
EBGP:256
3.相同路由协议情况下，选取metric最小的最优先匹配
每种协议metric值定义的都不相同，静态路由和路由优先级有关，这个是人为指定的，RIP协议和跳数有关，跳数越小越优先，OSPF协议和带宽有关，带宽最大最优先。metric是用来判定链路质量优劣的。
4.如果以上都没有路由可以匹配得上，就匹配默认路由
3.2 默认路由
作用：当路由在路由表中找不到目标网络的路由条目时，路由器把请求转发到默认路由接口
表示形式：0.0.0.0/0（所有网段）
使用条件：必须是末梢/末节网络，只能在末梢/末节网络中使用
默认路由是静态路由的一种特殊形式，它属于静态路由的一种
默认路由命令：[ ]ip route-static 0.0.0.0 0.0.0.0 10.1.1.2
出口网关的所有数据是丢给和出口网关对接的运营商路由器的入接口IP，需要配置默认路由
PC1:192.168.1.100 24设置IP地址和掩码长度
网关指向192.168.1.1
PC2:172.16.10.100 24设置IP地址和掩码长度
网关指向172.16.10.4
R1：
[ ]int g0/0/0进入接口g0/0/0
[ ]ip add 192.168.1.1 24设置IP地址和掩码长度
[ ]undo shutdown开启接口
[ ]int g0/0/1进入接口g0/0/1
[ ]ip add 10.1.1.1 24设置IP地址和掩码长度
[ ]undo shutdown开启接口
[ ]ip route-static 0.0.0.0 0.0.0.0 10.1.1.2添加默认路由网段0.0.0.0子网掩码0.0.0.0下一跳入接口IP10.1.1.2
R2：
[ ]int g0/0/0进入接口g0/0/0
[ ]ip add 10.1.1.2 24设置IP地址和掩码长度
[ ]undo shutdown开启接口
[ ]int g0/0/1进入接口g0/0/1
[ ]ip add 10.1.2.2 24设置IP地址和掩码长度
[ ]undo shutdown开启接口
[ ]ip route-static 192.168.1.0 24 10.1.1.1添加静态路由目的网段192.168.1.0子网掩码长度24下一跳入接口IP10.1.1.1
[ ]ip route-static 10.1.3.0 24 10.1.2.3添加静态路由目的网段10.1.3.0子网掩码长度24下一跳入接口IP10.1.2.3
[ ]ip route-static 172.16.10.0 24 10.1.2.3添加静态路由目的网段172.16.10.0子网掩码长度24下一跳入接口IP10.1.2.3
R3：
[ ]int g0/0/0进入接口g0/0/0
[ ]ip add 10.1.2.3 24设置IP地址和掩码长度
[ ]undo shutdown开启接口
[ ]int g0/0/1进入接口g0/0/1
[ ]ip add 10.1.3.3 24设置IP地址和掩码长度
[ ]undo shutdown开启接口
[ ]ip route-static 192.168.1.0 24 10.1.2.2添加静态路由目的网段192.168.1.0掩码长度24下一跳入接口IP10.1.1.2
[ ]ip route-static 10.1.1.0 24 10.1.2.2添加静态路由目的网段10.1.1.0掩码长度24下一跳入接口IP10.1.2.2
[ ]ip route-static 172.16.10.0 24 10.1.3.4添加静态路由目的网段172.16.10.0子网掩码长度24下一跳入接口IP10.1.3.4
R4:
[ ]int g0/0/0进入接口g0/0/0
[ ]ip add 10.1.3.4 24设置IP地址和掩码长度
[ ]undo shutdown开启接口
[ ]int g0/0/1进入接口g0/0/1
[ ]ip add 172.16.10.4 24设置IP地址和掩码长度
[ ]undo shutdown开启接口
[ ]ip route-static 0.0.0.0 0.0.0.0 10.1.3.3添加默认路由网段0.0.0.0子网掩码0.0.0.0下一跳入接口IP10.1.3.3
连通性测试:PC1 ping 172.16.10.4测试PC1和PC2能否通信
3.3 浮动路由
定义：指的是配置两条静态路由，默认选取链路质量优（带宽大的）作为主路径，当主路径出现故障时，由带宽较小的备份路径顶替主路径
作用：保持网络的不中断
浮动路由在同一时刻，数据只会由一条链路代为转发
浮动路由命令：①主路径：[ ]ip route-static 0.0.0.0 0 10.1.2.2
②备选路径：[ ]ip route-static 0.0.0.0 0 10.1.1.2 preference 65
PC>ping 172.16.1.10
Ping 172.16.1.10: 32 data bytes, Press Ctrl_C to break
From 172.16.1.10: bytes=32 seq=1 ttl=125 time=31 ms
From 172.16.1.10: bytes=32 seq=2 ttl=125 time=16 ms
From 172.16.1.10: bytes=32 seq=3 ttl=125 time=31 ms
From 172.16.1.10: bytes=32 seq=4 ttl=125 time=31 ms
From 172.16.1.10: bytes=32 seq=5 ttl=125 time=16 ms
--- 172.16.1.10 ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
round-trip min/avg/max = 16/25/31 ms
PC>tracert 172.16.1.10
traceroute to 172.16.1.10, 8 hops max
(ICMP), press Ctrl+C to stop
1 192.168.1.1 15 ms 16 ms <1 ms
2 10.1.1.2 47 ms 15 ms 32 ms
3 10.1.3.3 15 ms 31 ms 32 ms
4 *172.16.1.10 15 ms 16 ms
<Huawei>undo te
<Huawei>undo terminal mo
<Huawei>undo terminal monitor
Info: Current terminal monitor is off.
<Huawei>sys
<Huawei>system-view
Enter system view, return user view with Ctrl+Z.
[Huawei]sysn
[Huawei]sysname r1
[r1]us
[r1]user-in
[r1]user-interface co
[r1]user-interface console 0
[r1-ui-console0]id
[r1-ui-console0]idle-timeout 0 0
[r1-ui-console0]q
[r1]int g0/0/0
[r1-GigabitEthernet0/0/0]ip ad
[r1-GigabitEthernet0/0/0]ip address 192.168.1.1
^
Error:Incomplete command found at '^' position.
[r1-GigabitEthernet0/0/0]ip ad
[r1-GigabitEthernet0/0/0]ip address 192.168.1.1 24
[r1-GigabitEthernet0/0/0]un
[r1-GigabitEthernet0/0/0]undo sh
[r1-GigabitEthernet0/0/0]undo shutdown
Info: Interface GigabitEthernet0/0/0 is not shutdown.
[r1-GigabitEthernet0/0/0]int g0/0/1
[r1-GigabitEthernet0/0/1]ip ad
[r1-GigabitEthernet0/0/1]ip address 10.1.2.1 24
[r1-GigabitEthernet0/0/1]un
[r1-GigabitEthernet0/0/1]undo sh
[r1-GigabitEthernet0/0/1]undo shutdown
Info: Interface GigabitEthernet0/0/1 is not shutdown.
[r1-GigabitEthernet0/0/1]int e2/0/0
[r1-Ethernet2/0/0]ip ad
[r1-Ethernet2/0/0]ip address 10.1.1.1 24
[r1-Ethernet2/0/0]un
[r1-Ethernet2/0/0]undo sh
[r1-Ethernet2/0/0]undo shutdown
Info: Interface Ethernet2/0/0 is not shutdown.
[r1-Ethernet2/0/0]ping 192.168.1.10
PING 192.168.1.10: 56 data bytes, press CTRL_C to break
Reply from 192.168.1.10: bytes=56 Sequence=1 ttl=128 time=60 ms
Reply from 192.168.1.10: bytes=56 Sequence=2 ttl=128 time=20 ms
Reply from 192.168.1.10: bytes=56 Sequence=3 ttl=128 time=20 ms
Reply from 192.168.1.10: bytes=56 Sequence=4 ttl=128 time=10 ms
Reply from 192.168.1.10: bytes=56 Sequence=5 ttl=128 time=20 ms
--- 192.168.1.10 ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
round-trip min/avg/max = 10/26/60 ms
[r1-Ethernet2/0/0]ping 10.1.2.2
PING 10.1.2.2: 56 data bytes, press CTRL_C to break
Reply from 10.1.2.2: bytes=56 Sequence=1 ttl=255 time=60 ms
Reply from 10.1.2.2: bytes=56 Sequence=2 ttl=255 time=20 ms
Reply from 10.1.2.2: bytes=56 Sequence=3 ttl=255 time=20 ms
Reply from 10.1.2.2: bytes=56 Sequence=4 ttl=255 time=10 ms
Reply from 10.1.2.2: bytes=56 Sequence=5 ttl=255 time=20 ms
--- 10.1.2.2 ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
round-trip min/avg/max = 10/26/60 ms
[r1-Ethernet2/0/0]ping 10.1.1.2
PING 10.1.1.2: 56 data bytes, press CTRL_C to break
Reply from 10.1.1.2: bytes=56 Sequence=1 ttl=255 time=40 ms
Reply from 10.1.1.2: bytes=56 Sequence=2 ttl=255 time=30 ms
Reply from 10.1.1.2: bytes=56 Sequence=3 ttl=255 time=20 ms
Reply from 10.1.1.2: bytes=56 Sequence=4 ttl=255 time=30 ms
Reply from 10.1.1.2: bytes=56 Sequence=5 ttl=255 time=20 ms
--- 10.1.1.2 ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
round-trip min/avg/max = 20/28/40 ms
[r1-Ethernet2/0/0]q
[r1]ip ro
[r1]ip route-st
[r1]ip route-static 0.0.0.0 0 10.1.2.2
[r1]ip ro
[r1]ip route-st
[r1]ip route-static 0.0.0.0 0 10.1.1.2 pre
[r1]ip route-static 0.0.0.0 0 10.1.1.2 preference 65
[r1]int g0/0/1
[r1-GigabitEthernet0/0/1]sh
[r1-GigabitEthernet0/0/1]shutdown
[r1-GigabitEthernet0/0/1]q
[r1]save
^
Error: Unrecognized command found at '^' position.
[r1]q
<r1>save
The current configuration will be written to the device.
Are you sure to continue? (y/n)[n]:y
It will take several minutes to save configuration file, please wait.......
Configuration file had been saved successfully
Note: The configuration file will take effect after being activated
<r1>
<Huawei>undo te
<Huawei>undo terminal mo
<Huawei>undo terminal monitor
Info: Current terminal monitor is off.
<Huawei>sy
<Huawei>system-view
Enter system view, return user view with Ctrl+Z.
[Huawei]sysn
[Huawei]sysname r2
[r2]us
[r2]user-in
[r2]user-interface co
[r2]user-interface console 0
[r2-ui-console0]id
[r2-ui-console0]idle-timeout 0 0
[r2-ui-console0]q
[r2]int g0/0/1
[r2-GigabitEthernet0/0/1]ip ad
[r2-GigabitEthernet0/0/1]ip address 10.1.3.2 24
[r2-GigabitEthernet0/0/1]un
[r2-GigabitEthernet0/0/1]undo sh
[r2-GigabitEthernet0/0/1]undo shutdown
Info: Interface GigabitEthernet0/0/1 is not shutdown.
[r2-GigabitEthernet0/0/1]int g0/0/0
[r2-GigabitEthernet0/0/0]ip ad
[r2-GigabitEthernet0/0/0]ip address 10.1.2.2 24
[r2-GigabitEthernet0/0/0]un
[r2-GigabitEthernet0/0/0]undo sh
[r2-GigabitEthernet0/0/0]undo shutdown
Info: Interface GigabitEthernet0/0/0 is not shutdown.
[r2-GigabitEthernet0/0/0]int e2/0/0
[r2-Ethernet2/0/0]ip ad
[r2-Ethernet2/0/0]ip address 10.1.1.2 24
[r2-Ethernet2/0/0]un
[r2-Ethernet2/0/0]undo sh
[r2-Ethernet2/0/0]undo shutdown
Info: Interface Ethernet2/0/0 is not shutdown.
[r2-Ethernet2/0/0]ping 10.1.3.3
PING 10.1.3.3: 56 data bytes, press CTRL_C to break
Reply from 10.1.3.3: bytes=56 Sequence=1 ttl=255 time=60 ms
Reply from 10.1.3.3: bytes=56 Sequence=2 ttl=255 time=20 ms
Reply from 10.1.3.3: bytes=56 Sequence=3 ttl=255 time=30 ms
Reply from 10.1.3.3: bytes=56 Sequence=4 ttl=255 time=20 ms
Reply from 10.1.3.3: bytes=56 Sequence=5 ttl=255 time=20 ms
--- 10.1.3.3 ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
round-trip min/avg/max = 20/30/60 ms
[r2-Ethernet2/0/0]q
[r2]ip ro
[r2]ip route-st
[r2]ip route-static 192.168.1.0 24 10.1.2.1
[r2]ip ro
[r2]ip route-st
[r2]ip route-static 192.168.1.0 24 10.1.1.1 pre
[r2]ip route-static 192.168.1.0 24 10.1.1.1 preference 65
[r2]ip ro
[r2]ip route-st
[r2]ip route-static 172.16.1.0 24 10.1.3.3
[r2]q
<r2>save
The current configuration will be written to the device.
Are you sure to continue? (y/n)[n]:y
It will take several minutes to save configuration file, please wait.......
Configuration file had been saved successfully
Note: The configuration file will take effect after being activated
<r2> 
<Huawei>sy
<Huawei>system-view
Enter system view, return user view with Ctrl+Z.
[Huawei]sysn
[Huawei]sysname r3
[r3]user
[r3]user-in
[r3]user-interface co
[r3]user-interface console 0
[r3-ui-console0]id
[r3-ui-console0]idle-timeout 0 0
[r3-ui-console0]q
[r3]int g0/0/0
[r3-GigabitEthernet0/0/0]ip ad
[r3-GigabitEthernet0/0/0]ip address 10.1.3.3 24
[r3-GigabitEthernet0/0/0]un
[r3-GigabitEthernet0/0/0]undo sh
[r3-GigabitEthernet0/0/0]undo shutdown
Info: Interface GigabitEthernet0/0/0 is not shutdown.
[r3-GigabitEthernet0/0/0]int g0/0/1
[r3-GigabitEthernet0/0/1]ip ad
[r3-GigabitEthernet0/0/1]ip address 172.16.1.3 24
[r3-GigabitEthernet0/0/1]un
[r3-GigabitEthernet0/0/1]undo sh
[r3-GigabitEthernet0/0/1]undo shutdown
Info: Interface GigabitEthernet0/0/1 is not shutdown.
[r3-GigabitEthernet0/0/1]q
[r3]ip ro
[r3]ip route-st
[r3]ip route-static 0.0.0.0 0 10.1.3.2
[r3]q
<r3>save
The current configuration will be written to the device.
Are you sure to continue? (y/n)[n]:y
It will take several minutes to save configuration file, please wait.......
Configuration file had been saved successfully
Note: The configuration file will take effect after being activated
<r3>总结
路由表主要分为直连路由和非直连路由，直连路由是本地接口配置IP地址和子网掩码，接口开启后形成的路由，非直连路由不是本地接口配置IP地址和子网掩码接口开启后形成的路由
非直连路由的学习有两种方式：一种管理员手动添加叫静态路由，还有一种路由器通过路由协议自动学习叫动态路由，而默认路由是静态路由的一种特殊形式
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