在⼀台三层交换上，不同VLAN相互通信配置⽅法本实验需求：通过在cisco catalyst 3550来规划VLAN 100 和VLAN 200，并且配置DHCP 让VLAN100⼈事部计算机获得IP地址为192.168.0.0/24，让VLAN200市场部计算机获得IP地址为172.16.0.0/24。
因为市场部和⼈事部因为业务上的关系，需要两台服务器相互通信，所在还需要在3550上配置VLAN间相互通信。
实验拓扑：实验过程第⼀步配置Catalyst 3550基础配置复制代码代码如下:Switch>Switch>enableSwitch#conf tEnter configuration commands, one per line. End with CNTL/Z.Switch(config)#host 35503550(config)#no ip do lo3550(config)#line con 03550(config-line)#no exec-t3550(config-line)#logg syn3550(config-line)#exit第⼆步在Catalyst 3550 划分VLAN 100和VLAN 200 //进⼊全局配置模式下，划分VLAN(请问catalyst 3500⽀持在全局模式下划分VLAN吗？)复制代码代码如下:3550(config)#vlan 100//给VLAN100命名3550(config-vlan)#name renshibo3550(config-vlan)#int f0/133550(config-if)#switchport mode access3550(config-if)#switchport access vlan 1003550(config-if)#spanning-tree portfast//请问什么时候需要在交换机接⼝下配置portfast？这⾥如果不配置可以吗？%Warning: portfast should only be enabled on ports connected to a singlehost. Connecting hubs, concentrators, switches, bridges, etc... to thisinterface when portfast is enabled, can cause temporary bridging loops.Use with CAUTION%Portfast has been configured on FastEthernet0/13 but will onlyhave effect when the interface is in a non-trunking mode.3550(config-if)#vlan 2003550(config-vlan)#name shichangbo3550(config-vlan)#int f0/153550(config-if)#sw mo acc3550(config-if)#sw acc vlan 2003550(config-if)#spanning-tree portfast%Warning: portfast should only be enabled on ports connected to a singlehost. Connecting hubs, concentrators, switches, bridges, etc... to thisinterface when portfast is enabled, can cause temporary bridging loops.Use with CAUTION%Portfast has been configured on FastEthernet0/15 but will onlyhave effect when the interface is in a non-trunking mode.//验证VLAN的配置3550#show vlan briefVLAN Name Status Ports---- -------------------------------- --------- -------------------------------1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4Fa0/5, Fa0/6, Fa0/7, Fa0/8Fa0/9, Fa0/10, Fa0/11, Fa0/12Fa0/14, Fa0/16, Fa0/17, Fa0/18Fa0/23, Gi0/1, Gi0/2100 renshibo active Fa0/13200 shichangbo active Fa0/151002 fddi-default act/unsup1003 token-ring-default act/unsup1004 fddinet-default act/unsup1005 trnet-default act/unsup第三步配置SVI(交换虚拟接⼝)复制代码代码如下:3550#conf tEnter configuration commands, one per line. End with CNTL/Z.//进⼊VLAN 100 虚拟接⼝下3550(config)#int vlan 100//增加接⼝描述，以便将来排错更加⽅便3550(config-if)#description Connection to renshibo//这⾥配置的IP地址就是⼈事部PC的默认⽹关地址，如果VLAN接⼝不配置IP地址，后⾯的DHCP配置中，PC能否获得IP地址吗？？3550(config-if)#ip add 192.168.0.1 255.255.255.03550(config-if)#no sh3550(config-if)#int vlan 20000:13:22: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan200, changed state to up3550(config-if)#description Connection to shichangbo3550(config-if)#ip add 172.16.0.1 255.255.255.03550(config-if)#no sh3550(config-if)#3550#conf t//开启catalyst 3550三层交换路由功能（默认是关闭的）请问cisco catalyst那些型号交换机是三层交换机？3550(config)#ip routing3550(config)#exit3550#sh ip route//两条直连路由条⽬Codes: C - connected, S - static, R - RIP, M - mobile, B - BGPD - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter areaN1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGPi - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2ia - IS-IS inter area, * - candidate default, U - per-user static routeo - ODR, P - periodic downloaded static routeGateway of last resort is not set172.16.0.0/24 is subnetted, 1 subnetsC 172.16.0.0 is directly connected, Vlan200C 192.168.0.0/24 is directly connected, Vlan100Designated bridge has priority 32768, address ccd1.0a80.0000Designated port id is 129.65, designated path cost 0Timers: message age 0, forward delay 0, hold 0Number of transitions to forwarding state: 1BPDU: sent 993, received 92第四步在Catalyst 3550上配置DHCP，以便于VLAN100和VLAN200下客户端获得IP地址，掩码，⽹关，DNS等复制代码代码如下://全局下打开DHCP服务.默认是开启的吗？那为什么还要需要开启了？3550(config)#service dhcp//关闭dhcp 客户端IP冲突⽇志记录信息3550(config)#no ip dhcp conflict logging//配置地址池名称，地址池名称为任意字符（这⾥定义的名字VLAN的名称）3550(config)#ip dhcp pool renshibo//配置PC所获得⽹段地址范围，和掩码，（这⾥有⼏种命令语句格式）(network 192.168.0.0 255.255.255.0)3550(dhcp-config)#network 192.168.0.0 /24//配置⽹关地址3550(dhcp-config)#default-router 192.168.0.1//配置DNS（域名解析服务器）可选配置请问什么时候PC需要配置DNS地址？局域⽹通讯需要吗？3550(dhcp-config)#dns 218.30.19.40 61.134.1.4//配置域名3550(dhcp-config)#domain-name //配置地址租期为永久3550(dhcp-config)#lease infinite3550(dhcp-config)#exit//配置排除的IP地址范围，不从地址池内分配的地址，不配置排除地址可以吗？3550(config)#ip dhcp excluded-address 192.168.0.13550(config)#ip dhcp pool shichangbo3550(dhcp-config)#network 172.16.0.0 /243550(dhcp-config)#default-router 172.16.0.13550(dhcp-config)#dns 218.30.19.40 61.134.1.43550(dhcp-config)#domain-name 3550(dhcp-config)#lease infinite3550(dhcp-config)#exit3550(config)#ip dhcp excluded-address 172.16.0.1第五步在市场部PC上验证是否能从catalyst 3550获得IP地址, 如图：开始-运⾏-cmd-ipconfig /all第六步在Catalyst 3550查看PC获得的IP地址是否正确复制代码代码如下://查看DHCP绑定信息3550#sh ip dhcp bindingIP address Client-ID/ （MAC地址） Lease expiration TypeHardware address172.16.0.2 0100.16d3.249f.fd Infinite Automatic192.168.0.2 0100.1641.15e8.5c Infinite Automatic第七步在交换机测试是否可以ping通市场部和⼈事部PC复制代码代码如下:3550(config)#exit3550#00:26:41: %SYS-5-CONFIG_I: Configured from console by console3550#ping 172.16.0.2Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 172.16.0.2, timeout is 2 seconds:Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms3550#ping 192.168.0.2Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 192.168.0.2, timeout is 2 seconds:Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms第⼋步在市场部PC上⽤ping命令测试是否可以ping通VLAN100（⼈事部）下PC 如图：测试结果如下，可以ping通，实验现象成功！本⽂出⾃ “王万利的博客” 博客。
