实验中的IP划分：
   SW1 VLAN 2  192.168.2.250     VLAN 3    192.168.2.250
   SW2 VLAN 2  192.168.2.249     VLAN 3    192.168.2.249
   R1  bvi  1  192.168.2.251     bvi  2    192.168.3.251
   R2  bvi  1  192.168.2.248     bvi  2    192.168.3.248
       HSRP 2  192.168.2.254     HSRP 3    192.168.3.254
  
一。实验目的
    了解桥接的作用：桥接”，是指依据OSI网络模型的链路层的地址，对网络数据包进行转发的过程。当路由器配置了桥接选项后，会处理所有接口上的所有的数据帧，并实时调查每个主机的位置。若在某个接口上收入一个帧，就会在一个桥接内置入一个条目，列出发送数据的主机和接收到数据帧的接口MAC地址，这样路由表就被不断地在通信中完善起来。
参考：http://zhidao.baidu.com/question/5760460.html

二。实验内容
    1。在实验中，我们使用的是二层交换机，通过路由器来实现VLAN之间的路由
       在E0/0 E0/1下面划分子接口
       int e0/0.1         int e0/0.2
       en dot1q 2         en dot1q 3   分别封装VLAN 2 VLAN 3
    2。因为在同一物理接口不能配置同一网段的IP地址，我们要通过桥接组来实现子接口之间的桥接
       int e0/0.1            int e0/1.1
       bridge-group 1        bridge-group 2  建立两个桥接组
    3。这只是简单的两层桥接，要实现三层桥接，我们要给桥接组配置IP地址
       int bvi 1                              int bvi 2
       ip add 192.168.2.1 255.255.255.0       ip add 192.168.3.1 255.255.255.0
       两个组分别使用VLAN2 与VLAN 3的网段，这样可以实现VLAN之间的路由
    4。为了完成VLAN之间的路由，所有橙色线路的端口为trunk
       switchport mode truck
       switchport truck en do
    5。所有PC接入端号使作protfast 端口，接到收敛速成度
       spanning-stree protfast
    6。为了终端PC的安全，我们可以采用热备份协议，实现网关冗余
        R1: int bvi 1                              int bri 2
            standy 1 ip 192.168.2.254              standy 2 ip 192.168.3.254
            standy 1 pree                          standy 2 pree    开启抢占
       R2: int bvi 1

            standy 1 ip 192.168.2.254              standy 2 ip 192.168.3.254
            standy 1 pree                          standy 2 pree    开启抢占
            standy 1 pri 50 让R1成为VLAN 1主网关   standy 2 pri 200 让R2成为VLAN 2的主网关
       在第6中，我们分别分R1与R2成为VLAN 1与VLAN 2的主，彼此之间成为备份，使得网络更可靠
    7。ISP与本地路由器之间采用路由协议，可以实现负载均衡
在实验中用到如下命令：
   bridge 1 protocol ieee 封装协议
   birdge 1 route ip    　支持IP路由
　 birdge irb             将桥接接口集成路由功能

二。实验配置
    这个实验中，主要是难点是子接口的路由桥接，但这个设计早以最淘汰了，我们可以在三层路由来实现上面的功能 。另一个知识点就是为这个VLAN 建立备份网关，我们可以采用HSRP VRRP GLBP协议来实现

 

三．配置

R1-up#sh run
Building configuration...

Current configuration : 1119 bytes
!
version 12.3
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname R1-up
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
ip subnet-zero
!
!
!
ip cef
bridge irb
!
!
!
interface Loopback1
 ip address 1.1.1.1 255.255.255.0
!
interface Ethernet0/0
 no ip address
 half-duplex
!
interface Ethernet0/0.1
 encapsulation dot1Q 2
 bridge-group 1
!
interface Ethernet0/0.2
 encapsulation dot1Q 3
 bridge-group 2
!
interface Serial0/0
 ip address 10.1.1.1 255.255.255.0
 no fair-queue
!
interface Ethernet0/1
 no ip address
 half-duplex
!
interface Ethernet0/1.1
 encapsulation dot1Q 2
 bridge-group 1
!
interface Ethernet0/1.2
 encapsulation dot1Q 3
 bridge-group 2
!
interface BVI1
 ip address 192.168.2.251 255.255.255.0
 standby 1 ip 192.168.2.1
 standby 1 preempt
!
interface BVI2
 ip address 192.168.3.251 255.255.255.0
 standby 2 ip 192.168.3.1
!
ip http server
ip classless
!
!
!
!
bridge 1 protocol ieee
bridge 1 route ip
bridge 2 protocol ieee
bridge 2 route ip
!
!
!
!
line con 0
line aux 0
line vty 0 4
 login
!
!
end

R2-down#sh run
Building configuration...

Current configuration : 1173 bytes
!
version 12.3
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname R2-down
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
ip subnet-zero
ip cef
!
!
!
ip audit po max-events 100
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
bridge irb
!
!
!
interface Ethernet0/0
 no ip address
 half-duplex
!
interface Ethernet0/0.1
 encapsulation dot1Q 2
 bridge-group 1
!
interface Ethernet0/0.2
 encapsulation dot1Q 3
 bridge-group 2
!
interface Serial0/0
 no ip address
 shutdown
 no fair-queue
!
interface Ethernet0/1
 no ip address
 half-duplex
!
interface Ethernet0/1.1
 encapsulation dot1Q 2
 bridge-group 1
!
interface Ethernet0/1.2
 encapsulation dot1Q 3
 bridge-group 2
!
interface BVI1
 ip address 192.168.2.248 255.255.255.0
 standby 1 ip 192.168.2.1
 standby 1 priority 50
 standby 1 preempt

//桥接组1 并启用了HSRP
!
interface BVI2
 ip address 192.168.3.248 255.255.255.0
 standby 2 ip 192.168.3.1
 standby 2 priority 200
 standby 2 preempt

//桥接组2 并启用了HSRP
!
ip http server
no ip http secure-server
ip classless
!
!
!
bridge 1 protocol ieee
bridge 1 route ip
bridge 2 protocol ieee
bridge 2 route ip
!
!
!
!
!
line con 0
line aux 0
line vty 0 4
!
!
end

 

 

Sw1-up#sh run
Building configuration...

Current configuration:
!
version 12.0
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname Sw1-up
!
!
!
!
!
!
!
ip subnet-zero
!
!
!
interface FastEthernet0/1
 switchport trunk encapsulation dot1q
 switchport mode trunk
!
interface FastEthernet0/2
 switchport trunk encapsulation dot1q
 switchport mode trunk
!
interface FastEthernet0/3
!
interface FastEthernet0/4
!
interface FastEthernet0/5
!
interface FastEthernet0/6
!
interface FastEthernet0/7
!
interface FastEthernet0/8
!
interface FastEthernet0/9
!
interface FastEthernet0/10
 switchport access vlan 2
 spanning-tree portfast
!
interface FastEthernet0/11
!
interface FastEthernet0/12
!
interface VLAN1
 no ip directed-broadcast
 no ip route-cache
!
interface VLAN2
 ip address 192.168.2.250 255.255.255.0
 no ip directed-broadcast
 no ip route-cache
!
interface VLAN3
 ip address 192.168.3.250 255.255.255.0
 no ip directed-broadcast
 no ip route-cache
!
!
line con 0
 transport input none
 stopbits 1
line vty 0 4
 login
line vty 5 15
 login
!
end

Sw1-up#

 

Sw2-down#sh run
Building configuration...

Current configuration:
!
version 12.0
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname Sw2-down
!
!
!
!
!
!
!
ip subnet-zero
!
!
!
interface FastEthernet0/1
 switchport trunk encapsulation dot1q
 switchport mode trunk
 spanning-tree portfast
!
interface FastEthernet0/2
 switchport trunk encapsulation dot1q
 switchport mode trunk
 spanning-tree portfast
!
interface FastEthernet0/3
 spanning-tree portfast
!
interface FastEthernet0/4
 spanning-tree portfast
!
interface FastEthernet0/5
 spanning-tree portfast
!
interface FastEthernet0/6
 spanning-tree portfast
!
interface FastEthernet0/7
 spanning-tree portfast
!
interface FastEthernet0/8
 spanning-tree portfast
!
interface FastEthernet0/9
 spanning-tree portfast
!
interface FastEthernet0/10
 spanning-tree portfast
!
interface FastEthernet0/11
 spanning-tree portfast
!
interface FastEthernet0/12
 spanning-tree portfast
!
interface VLAN1
 no ip directed-broadcast
 no ip route-cache
!
interface VLAN2
 ip address 192.168.2.249 255.255.255.0
 no ip directed-broadcast
 no ip route-cache
!
interface VLAN3
 ip address 192.168.3.249 255.255.255.0
 no ip directed-broadcast
 no ip route-cache
!
!
line con 0
 transport input none
 stopbits 1
line vty 0 4
 login
line vty 5 15
 login
!
end

Sw2-down#