三层交换技术：二层交换技术+三层转发技术。它解决了局域网中网段划分之后，网段中子网必须依赖路由器进行管理的局面，解决了传统路由器低速、复杂所造成的网络瓶颈问题。
实验需求：
- C1和C4属于VLAN10，C2、C3属于VLAN20；
- 三层交换实现PC间互通；
- R2配置静态路由实现全网互通；
实验步骤：
实验所用 ：Cisco GNS3
1.SW1配置
SW1#confi t //进入全局配置模式;
Enter configuration commands, one per line. End with CNTL/Z.
SW1(config)#vlan 10,20 //批量添加VLAN;
SW1(config-vlan)#exit
SW1(config)#int f1/1 //进入物理接口fa1/1;
SW1(config-if)#switchport access vlan 10 //添加VLAN10;
SW1(config-if)#no shut //激活端口;
SW1(config)#int f1/2 //进入接口fa1/2;
SW1(config-if)#switchport access vlan 20 //添加VLAN20;
SW1(config-if)#no shut //激活端口;
SW1(config)#int f1/5 //进入接口fa1/5;
SW1(config-if)#switchport mode trunk //中继TRUNK口;
SW1(config-if)#
*Mar 1 00:35:23.195: %DTP-5-TRUNKPORTON: Port Fa1/5 has become dot1q trunk
SW1(config)#int f1/0 //进入接口fa1/0;
SW1(config-if)#switchport mode trunk //中继TRUNK口;
SW1(config-if)#
*Mar 1 00:39:33.223: %DTP-5-TRUNKPORTON: Port Fa1/0 has become dot1q trunk
2.SW2配置
SW2#confi t //全局配置模式
Enter configuration commands, one per line. End with CNTL/Z.
SW2(config)#vlan 10,20 //批量添加VLAN;
SW2(config-vlan)#exit
SW2(config)#int f1/3 //进接口fa1/3;
SW2(config-if)#switchport access vlan 20 //添加VLAN20;
SW2(config-if)#no shut //激活端口;
SW2(config)#int f1/5 //进fa1/5端口;
SW2(config-if)#switchport mode trunk //配置中继端口;
SW2(config-if)#
*Mar 1 00:36:20.659: %DTP-5-TRUNKPORTON: Port Fa1/5 has become dot1q trunk
3.M1配置
M1#confi t //全局配置模式;
Enter configuration commands, one per line. End with CNTL/Z.
M1(config)#int f1/0 //进接口fa1/0;
M1(config-if)#switchport mode trunk //配置中继TRUNK;
M1(config-if)#
*Mar 1 00:41:48.443: %DTP-5-TRUNKPORTON: Port Fa1/0 has become dot1q trunk
M1(config-if)#exit
M1(config)#vlan 10,20 //批量添加VLAN;
M1(config-vlan)#exit
M1(config)#int f1/4 //进接口fa1/4;
M1(config-if)#switchport access vlan 10 //添加VLAN10;
M1(config)#int vlan10 //进入VLAN10虚拟接口;
*Mar 1 00:44:50.479: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan10, changed state to up
M1(config-if)#ip addr 192.168.1.1 255.255.255.0 //配置网关IP地址;
M1(config-if)#int vlan20 //进入VLAN20虚拟接口;
*Mar 1 00:45:24.131: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan20, changed state to up
M1(config-if)#ip addr 192.168.2.1 255.255.255.0 //配置网关IP地址;
M1(config)#int f1/10 //进接口fa1/10;
M1(config-if)#no switchport //二层端口转三层端口;
M1(config-if)#ip add 10.0.0.1 255.255.255.0 //配置IP地址;
M1(config-if)#
*Mar 1 00:54:19.367: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet1/10, changed state to up
M1(config-if)#no shut //端口激活;
M1(config)#ip route 0.0.0.0 0.0.0.0 10.0.0.2 //配置默认静态路由;
4.PC配置
VPCS[1]> ip 192.168.1.10 192.168.1.1 //配置C1 IP地址及网关;
Checking for duplicate address...
PC1 : 192.168.1.10 255.255.255.0 gateway 192.168.1.1
VPCS[1]> 2
VPCS[2]> ip 192.168.2.20 192.168.2.1 //配置C2 IP地址及网关;
Checking for duplicate address...
PC2 : 192.168.2.20 255.255.255.0 gateway 192.168.2.1
VPCS[2]> 3
VPCS[3]> ip 192.168.2.30 192.168.2.1 //配置C3 IP地址及网关;
Checking for duplicate address...
PC3 : 192.168.2.30 255.255.255.0 gateway 192.168.2.1
VPCS[3]> 4
VPCS[4]> ip 192.168.1.40 192.168.1.1 //配置C4 IP地址及网关;
Checking for duplicate address...
PC4 : 192.168.1.40 255.255.255.0 gateway 192.168.1.1
5.测试PC间通信
VPCS[4]> ping 192.168.1.10 //测试C1和C4连通性;
192.168.1.10 icmp_seq=1 ttl=64 time=2.002 ms
192.168.1.10 icmp_seq=2 ttl=64 time=2.967 ms
192.168.1.10 icmp_seq=3 ttl=64 time=2.003 ms
192.168.1.10 icmp_seq=4 ttl=64 time=3.008 ms
192.168.1.10 icmp_seq=5 ttl=64 time=2.003 ms
VPCS[4]> 3
VPCS[3]> ping 192.168.2.20 //测试C3、C2连通性;
192.168.2.20 icmp_seq=1 ttl=64 time=3.004 ms
192.168.2.20 icmp_seq=2 ttl=64 time=2.069 ms
VPCS[3]> ping 192.168.1.10 //测试C3、C1连通性;
192.168.1.10 icmp_seq=1 timeout
192.168.1.10 icmp_seq=2 ttl=63 time=17.949 ms
192.168.1.10 icmp_seq=3 ttl=63 time=17.967 ms
192.168.1.10 icmp_seq=4 ttl=63 time=55.063 ms
192.168.1.10 icmp_seq=5 ttl=63 time=28.966 ms
VPCS[3]>
VPCS[3]> 4
VPCS[4]> ping 192.168.2.20 //测试C4、C2连通性;
192.168.2.20 icmp_seq=1 timeout
192.168.2.20 icmp_seq=2 ttl=63 time=47.050 ms
192.168.2.20 icmp_seq=3 ttl=63 time=23.026 ms
6.R1配置
R1#confi t //全局配置模式;
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#int f0/1 //进fa0/1接口;
R1(config-if)#ip add 10.0.0.2 255.255.255.0 //配置IP地址及子网掩码;
R1(config-if)#no shut //激活端口;
R1(config-if)#
*Mar 1 00:55:56.307: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to up
*Mar 1 00:55:57.307: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up
R1(config)#int f0/0 //进入接口FA0/0;
R1(config-if)#ip add 12.0.0.2 255.255.255.0 //配置IP地址、子网掩码;
R1(config-if)#no shut //激活端口;
R1(config-if)#
*Mar 1 00:58:54.163: %LINK-3-UPDOWN: Interface FastEthernet0/0, changed state to up
*Mar 1 00:58:55.163: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to up
R1(config)#ip route 192.168.1.0 255.255.255.0 10.0.0.1 //配置默认静态路由;
R1(config)#ip route 192.168.2.0 255.255.255.0 10.0.0.1
7.R2配置
R2#confi t //全局配置模式;
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#int f0/0 //进入f0/0接口;
R2(config-if)#ip add 12.0.0.3 255.255.255.0 //配置IP地址及子网掩码;
R2(config-if)#no shut //激活端口;
R2(config-if)#
*Mar 1 01:00:11.707: %LINK-3-UPDOWN: Interface FastEthernet0/0, changed state to up
*Mar 1 01:00:12.707: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to up
R2(config)#ip route 0.0.0.0 0.0.0.0 12.0.0.2 //配置静态路由;
8.测试互通
VPCS[3]> ping 12.0.0.3 //测试C3、R2连通性;
12.0.0.3 icmp_seq=1 ttl=253 time=137.756 ms
12.0.0.3 icmp_seq=2 ttl=253 time=93.753 ms
12.0.0.3 icmp_seq=3 ttl=253 time=109.381 ms
12.0.0.3 icmp_seq=4 ttl=253 time=140.631 ms
12.0.0.3 icmp_seq=5 ttl=253 time=140.633 ms
VPCS[3]> 1
VPCS[1]> ping 12.0.0.2 //测试C1、R1连通性;
12.0.0.2 icmp_seq=1 ttl=254 time=62.501 ms
12.0.0.2 icmp_seq=2 ttl=254 time=93.764 ms
12.0.0.2 icmp_seq=3 ttl=254 time=78.126 ms
12.0.0.2 icmp_seq=4 ttl=254 time=78.126 ms
12.0.0.2 icmp_seq=5 ttl=254 time=93.756 ms