通过本实验掌握如何给不同网段配置 DHCP ，掌握 DHCP 中继配置，了解ip help-address 作用,了解Cisco 路由器的DHCP的配置。也许你会配置DHCP，可是可能遇到的情况是很顺利，有时你的DHCP服务器，和你DHCP 客户端，并不是在同一个网段，而是需要DHCP 给不同的网段主机分配地址。
实验拓扑 :
实验过程：
第一步： 对路由器 R1 进行预配置
| Router(config)# no ip do lo Router(config)# line con 0 Router(config-line)# no exec-t Router(config-line)# logg syn Router(config-line)# host R1 R1(config)# do sh ip int bri Interface IP-Address OK? Method Status Protocol Ethernet0/0 unassigned YES unset administratively down down Serial0/0 unassigned YES unset administratively down down Ethernet1/0 unassigned YES unset administratively down down Serial1/0 unassigned YES unset administratively down down R1(config)# int e0/0 // 配置接口的下描述信息 R1(config-if)# description Connection to R2_E0/0 R1(config-if) #ip add 12.0.0.1 255.255.255.0 R1(config-if)# no sh R1(config-if)# end R1(config)# int e1/0 R1(config-if)# description Connection to PC1 R1(config-if)# ip address 192.168.1.1 255.255.255.0 R1(config-if)# no sh R1(config-if)# *Mar 1 00:32:04.807: %LINK-3-UPDOWN: Interface Ethernet1/0, changed state to up *Mar 1 00:32:05.807: %LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet1/0, changed state to up R1(config-if)#*Mar 1 00:09:16.631: %SYS-5-CONFIG_I: Configured from console by console R1#conf t *Mar 1 00:09:17.499: %LINK-3-UPDOWN: Interface Ethernet0/0, changed state to up R1#conf t Enter configuration commands, one per line. End with CNTL/Z. // 配置远程登录的用户名和密码，如果用户的级别为15 ，远程登录之后可以直接进入特权模式下 R1(config)# username admin privilege 15 password admin R1(config)# line vty 0 4 R1(config-line)# login local R1(config-line)# end R1# R1# |
第二步： 对路由器 R2 进行预配置
| Router> en Router# conf t Enter configuration commands, one per line. End with CNTL/Z. Router(config)# host R2 R2(config)# no ip do lo R2(config)# line con 0 R2(config-line)# no exec-t R2(config-line)# logg syn R2(config-line)# int e0/0 R1(config-if)# description Connection to R1_E0/0 R2(config-if)# ip add 12.0.0.2 255.255.255.0 R2(config-if)# no sh R2(config-if)# exit *Mar 1 00:10:09.331: %LINK-3-UPDOWN: Interface Ethernet0/0, changed state to up *Mar 1 00:10:10.331: %LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet0/0, changed state to up R2(config)# username admin privilege 15 password admin R2(config)# line vty 0 15 R2(config-line)# login local R2(config-line)# end *Mar 1 00:10:21.363: %SYS-5-CONFIG_I: Configured from console by console R2# ping 12.0.0.1 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 12.0.0.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 4/4/4 ms R2# |
第三步：在 R1 运行动态路由协议，配置 DHCP
| R1#conf t Enter configuration commands, one per line. End with CNTL/Z. // 配置动态路由协议，保证两个不同的网段可以相互通信 R1(config)# router rip R1(config-router)# ver 2 R1(config-router)# no au R1(config-router)# net 12.0.0.1 R1(config-router)# net 192.168.1.1 R1(config-router)# exit // 开启DCHP 服务 R1(config)# service dhcp R1(config)# no ip dhcp conflict logging R1(config)# ip dhcp pool PC1_Subnet R1(dhcp-config)# network 192.168.1.0 /24 R1(dhcp-config)# default-router 192.168.1.1 R1(dhcp-config)# domain-name cisco.com R1(dhcp-config)# dns-server 218.30.19.40 61.134.1.4 R1(dhcp-config)# option 150 ip 192.168.1.10 R1(dhcp-config)# lease 7 R1(dhcp-config)# exit R1(config)# ip dhcp excluded-address 192.168.1.1 R1(config)# ip dhcp excluded-address 192.168.1.10 R1(config)# ip dhcp pool PC2_Subnet R1(dhcp-config)# network 172.16.1.0 /24 R1(dhcp-config)# default-router 172.16.1.1 R1(dhcp-config)# domain-name norvel.com R1(dhcp-config)# dns-server 218.30.19.40 61.134.1.4 R1(dhcp-config)# option 150 ip 172.16.1.10 R1(dhcp-config)# lease 7 R1(dhcp-config)# exit R1(config)# ip dhcp excluded-address 172.16.1.1 R1(config)# ip dhcp excluded-address 172.16.1.10 R1# show run | b ip dhcp no ip dhcp conflict logging ip dhcp excluded-address 192.168.1.1 ip dhcp excluded-address 192.168.1.10 ip dhcp excluded-address 172.16.1.1 ip dhcp excluded-address 172.16.1.10 ip dhcp pool PC1_Subnet network 192.168.1.0 255.255.255.0 default-router 192.168.1.1 domain-name cisco.com dns-server 218.30.19.40 61.134.1.4 option 150 ip 192.168.1.10 lease 7 ip dhcp pool PC2_Subnet network 172.16.1.0 255.255.255.0 default-router 172.16.1.1 domain-name norvel.com dns-server 218.30.19.40 61.134.1.4 option 150 ip 172.16.1.10 lease 7 R1(config)# |
第四步：在 R2 运行动态路由协议，配置辅助地址
| R1# telnet 12.0.0.2 Trying 12.0.0.2 ... Open User Access Verification Username: admin Password: R2#conf t Enter configuration commands, one per line. End with CNTL/Z. R2(config)# int e1/0 R2(config-if)# ip ad 172.16.1.1 255.255.255.0 R2(config-if)# no sh R2(config-if)# router rip R2(config-router)# ver 2 R2(config-router)# no au R2(config-router)# net 12.0.0.2 R2(config-router)# net 172.16.1.1 R2(config-router)# exit R2(config)# int e1/0 // 配置DHCP 中继地址 R2(config-if)# ip helper-address 12.0.0.1 R2(config-if)# R1# sh ip int bri Interface IP-Address OK? Method Status Protocol Ethernet0/0 12.0.0.1 YES manual up up Serial0/0 unassigned YES unset administratively down down Ethernet1/0 192.168.1.1 YES manual up up Serial1/0 unassigned YES unset administratively down down |
第五步：在 PC1 和 PC2 上查看获得 IP 地址信息
开始 - 运行 -cmd-ipconfig /all
如图： PC2
如图： PC1
第六步：查看交换机 IP 地址池和动态绑定信息
| R1# show ip dhcp binding Bindings from all pools not associated with VRF: IP address Client-ID/ Lease expiration Type Hardware address/ User name 172.16.1.2 0100.8045.2984.f2 Mar 08 1993 12:52 AM Automatic 192.168.1.2 0100.16d3.249f.fd Mar 08 1993 12:51 AM Automatic R1# R1# show ip dhcp pool Pool PC1_Subnet : Utilization mark (high/low) : 100 / 0 Subnet size (first/next) : 0 / 0 Total addresses 254 Leased addresses 1 Pending event none 1 subnet is currently in the pool : Current index IP address range Leased addresses 192.168.1.3 192.168.1.1 - 192.168.1.254 1 Pool PC2_Subnet : Utilization mark (high/low) : 100 / 0 Subnet size (first/next) : 0 / 0 Total addresses : 254 Leased addresses : 1 Pending event : none 1 subnet is currently in the pool : Current index IP address range Leased addresses 172.16.1.3 172.16.1.1 - 172.16.1.254 1 R1# R1# sh ip ro Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route Gateway of last resort is not set 172.16.0.0/24 is subnetted, 1 subnets R 172.16.1.0 [120/1] via 12.0.0.2, 00:00:24, Ethernet0/0 12.0.0.0/24 is subnetted, 1 subnets C 12.0.0.0 is directly connected, Ethernet0/0 C 192.168.1.0/24 is directly connected, Ethernet1/0 R1# debug ip dhcp server events R1# *Mar 1 01:12:33.367: DHCPD: assigned IP address 172.16.1.2 to client 0100.8045.2984.f2. R1# telnet 12.0.0.2 Trying 12.0.0.2 ... Open User Access Verification Username: admin Password: R2# sh run int e1/0 interface Ethernet1/0 ip address 172.16.1.1 255.255.255.0 ip helper-address 12.0.0.1 half-duplex |
第七步:测试全网互联互通
| C:\ ping 172.16.1.1 Pinging 172.16.1.1 with 32 bytes of data: Reply from 172.16.1.1: bytes=32 time=2ms TTL=255 Reply from 172.16.1.1: bytes=32 time=2ms TTL=255 Ping statistics for 172.16.1.1: Packets: Sent = 2, Received = 2, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 2ms, Maximum = 2ms, Average = 2ms Control-C ^C C:\ ping 12.0.0.2 Pinging 12.0.0.2 with 32 bytes of data: Reply from 12.0.0.2: bytes=32 time=2ms TTL=255 Ping statistics for 12.0.0.2: Packets: Sent = 1, Received = 1, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 2ms, Maximum = 2ms, Average = 2ms Control-C ^C C:\ ping 12.0.0.1 Pinging 12.0.0.1 with 32 bytes of data: Reply from 12.0.0.1: bytes=32 time=2ms TTL=254 Reply from 12.0.0.1: bytes=32 time=2ms TTL=254 Ping statistics for 12.0.0.1: Packets: Sent = 2, Received = 2, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 2ms, Maximum = 2ms, Average = 2ms Control-C ^C C:\ping 192.168.1.1 Pinging 192.168.1.1 with 32 bytes of data: Reply from 192.168.1.1: bytes=32 time=3ms TTL=254 Ping statistics for 192.168.1.1: Packets: Sent = 1, Received = 1, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 3ms, Maximum = 3ms, Average = 3ms Control-C ^C C:\ping 192.168.1.2 Pinging 192.168.1.2 with 32 bytes of data: Reply from 192.168.1.2: bytes=32 time=5ms TTL=126 Ping statistics for 192.168.1.2: Packets: Sent = 1, Received = 1, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 5ms, Maximum = 5ms, Average = 5ms Control-C ^C |