单臂路由(router-on-a-stick)是指在路由器的一个接口上通过配置子接口(或“逻辑接口”,并不存在真正物理接口)的方式,实现原来相互隔离的不同VLAN(虚拟局域网)之间的互联互通。

环境

  • Cisco Packet Tracer 5.3
  • Windows 10

    操作

    操作:按照如图所示连接拓扑图
    image.png

    实验步骤

    (1)创建拓扑,配置设备
    添加一台路由器、一台交换机和四台主机


    PC0和PC1与交换机fa0/1、fa0/2 接口连接,划分在VLAN10中,IP分别为192.168.10.1、192.168.10.2,网关192.168.10.254。
    PC2和PC3与交换机fa0/11、fa0/12 接口连接,划分在VLAN20中,IP分别为192.168.20.1、192.168.20.2,网关192.168.20.254。
    交换机fa0/24端口与路由器fa0/1端口连接。


    (2)配置交换机

    /* Part 1 配置交换机 */
    Switch>enable
    Switch#configure terminal
    Switch(config)#hostname SA
    SA(config)#vlan 10
    SA(config-vlan)#vlan 20
    SA(config-vlan)#exit
    SA(config)#interface range fa0/1-fa0/2
    SA(config-if-range)#switchport access vlan 10
    SA(config-if-range)#interface range fa0/11-fa0/12
    SA(config-if-range)#switchport access vlan 20
    SA(config-if-range)#interface fa0/24
    SA(config-if)#switchport mode trunk
    SA(config-if)#switchport trunk allowed vlan all
    
    /* Part 2 检查配置 */
    SA(config-if-range)#^Z         (Ctrl+Z组合键)
    SA#show vlan
    ...
    VLAN Name                             Status    Ports
  • default active Fa0/3, Fa0/4, Fa0/5, Fa0/6

                                              Fa0/7, Fa0/8, Fa0/9, Fa0/10
                                              Fa0/13, Fa0/14, Fa0/15, Fa0/16
                                              Fa0/17, Fa0/18, Fa0/19, Fa0/20
                                              Fa0/21, Fa0/22, Fa0/23
  • VLAN0010 active Fa0/1, Fa0/2
  • VLAN0020 active Fa0/11, Fa0/12
    ...

    (3)配置路由器

    / Part 1 配置路由器 /
    Router>enable
    Router#configure terminal
    Router(config)#hostname RA
    RA(config)#interface fa0/0.1
    RA(config-subif)#encapsulation dot1Q 10
    // (1:在路由器上配置trunk的封装协议的命令:
    // encapsulation [isl/dot1q] vlan#
    // 2:上面的路由器配置了dot1q中继封装,10是vlan 10。
    // 3:Trunk的封装类型一共有 ISL和802.1Q两种,而802.1Q在输入的时候为dot1q)
    RA(config-subif)#ip address 192.168.10.254 255.255.255.0
    RA(config-subif)#interface fa0/0.2
    RA(config-subif)#encapsulation dot1Q 20
    RA(config-subif)#ip address 192.168.20.254 255.255.255.0
    RA(config-subif)#exit
    RA(config)#interface fa0/0
    RA(config-if)#shutdown
    RA(config-if)#no shutdown     //(重启fa0/0接口)

    / Part 2 检查配置 /
    RA>show interfaces fa0/0.1
    ...
    Internet address is 192.168.1.254/24
    ...
    Encapsulation 802.1Q Virtual LAN, Vlan ID 10
    ...

    RA>show interfaces fa0/0.2
    ...
    Internet address is 192.168.2.254/24
    ...
    Encapsulation 802.1Q Virtual LAN, Vlan ID 20
    ...

    (4)连通性测试

    / Part 1 PC0 Ping 自己网关 /
    PC>ping 192.168.1.254

    Pinging 192.168.1.254 with 32 bytes of data:

    Reply from 192.168.1.254: bytes=32 time=11ms TTL=255
    Reply from 192.168.1.254: bytes=32 time=12ms TTL=255
    Reply from 192.168.1.254: bytes=32 time=11ms TTL=255
    Reply from 192.168.1.254: bytes=32 time=12ms TTL=255

    Ping statistics for 192.168.1.254:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
    Approximate round trip times in milli-seconds:
    Minimum = 11ms, Maximum = 12ms, Average = 11ms

    / Part 2 PC0 Ping PC1 /
    PC>ping 192.168.1.2

    Pinging 192.168.1.2 with 32 bytes of data:

    Reply from 192.168.1.2: bytes=32 time=25ms TTL=128
    Reply from 192.168.1.2: bytes=32 time=10ms TTL=128
    Reply from 192.168.1.2: bytes=32 time=12ms TTL=128
    Reply from 192.168.1.2: bytes=32 time=14ms TTL=128

    Ping statistics for 192.168.1.2:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
    Approximate round trip times in milli-seconds:
    Minimum = 10ms, Maximum = 25ms, Average = 15ms

    / Part 3 PC0 Ping PC2 PC3网关 /
    PC>ping 192.168.2.254

    Pinging 192.168.2.254 with 32 bytes of data:

    Reply from 192.168.2.254: bytes=32 time=11ms TTL=255
    Reply from 192.168.2.254: bytes=32 time=14ms TTL=255
    Reply from 192.168.2.254: bytes=32 time=11ms TTL=255
    Reply from 192.168.2.254: bytes=32 time=12ms TTL=255

    Ping statistics for 192.168.2.254:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
    Approximate round trip times in milli-seconds:
    Minimum = 11ms, Maximum = 14ms, Average = 12ms

    / Part 4 PC0 Ping PC2 /
    PC>ping 192.168.2.1

    Pinging 192.168.2.1 with 32 bytes of data:

    Reply from 192.168.2.1: bytes=32 time=24ms TTL=127
    Reply from 192.168.2.1: bytes=32 time=19ms TTL=127
    Reply from 192.168.2.1: bytes=32 time=21ms TTL=127
    Reply from 192.168.2.1: bytes=32 time=20ms TTL=127

    Ping statistics for 192.168.2.1:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
    Approximate round trip times in milli-seconds:
    Minimum = 19ms, Maximum = 24ms, Average = 21ms

    / Part 5 PC0 Ping PC3 /
    PC>ping 192.168.2.2

    Pinging 192.168.2.2 with 32 bytes of data:

    Request timed out.
    Reply from 192.168.2.2: bytes=32 time=24ms TTL=127
    Reply from 192.168.2.2: bytes=32 time=22ms TTL=127
    Reply from 192.168.2.2: bytes=32 time=19ms TTL=127

    Ping statistics for 192.168.2.2:
    Packets: Sent = 4, Received = 3, Lost = 1 (25% loss),
    Approximate round trip times in milli-seconds:
    Minimum = 19ms, Maximum = 24ms, Average = 21ms

    <a name="F1D2o"></a>
    ## 结论
    由实验可知,划分VLAN后不同VLAN间的主机不能通信,可以使用路由器进行VLAN间通信。
    > 注意:
    > 1、主机需要配网关。
    > 2、当出现Ping不通别的主机时,可以采用由近及远的检查方式,即依次Ping自己、自己的网关、对方主机的网关、对方主机以便于发现错误位置。

实验工程

单臂路由.zip

最后修改:2020 年 06 月 19 日
如果觉得我的文章对你有用,请随意赞赏