子网划分专项练习.docx

1、子网划分专项练习子网划分专项练习计网1032班 谭福庆 学号10250532111.What valid host range is the IP address 172.16.10.22 255.255.255.240 a part of?（在172.16.10.22 255.255.255.240这个网络里，有效IP地址的范围是？）A.172.16.10.20 through 172.16.10.22B. 172.16.10.1 through 172.16.10.255C. 172.16.10.16 through 172.16.10.23D. 172.16.10.17 through

2、172.16.10.31E. 172.16.10.17 through 172.16.10.30答案:E.解析：根据这个IP地址可知：这是一个B类地址，由子网掩码可知，172.16.10.22255.255.255.240二进制如下10101100.00010000.00001100.0001010011111111.11111111.11111111.11110000-进行与运算10101100.00010000.00001100.00010000 网络地址得到广播地址如下：10101100.00010000.00001100.00011111 广播地址0001111116+8+4+2+1=

3、31有效IP地址的范围为17-312. What is the broadcast address of the subnet address 172.16.8.159 255.255.255.192?（在172.16.8.159 255.255.255.192这个网络里，广播地址是？）A. 172.16.255.255B. 172.16.8.127C. 172.16.8.191D. 172.16.8.255 答案：C.解析：1. 求网络地址/网络ipip与mask：172.16.8.159255.255.255.192-10101100.00010000.00001000.100111111

4、1111111.11111111.11111111.11000000-10101100.00010000.00001000.10000000 网络ip2.得出主机位11111111.11111111.11111111.11 000000主机位是最后6位3.把主机位全置16个14.网络地址+主机位全为1=广播地址10101100.00010000.00001000.10111111 广播地址172.16.8.1913. What is the broadcast address of the subnet address 192.168.10.33 255.255.255.248?（在192.1

5、68.10.33 255.255.255.248这个网络里，广播地址是？）A. 192.168.10.40B. 192.168.10.255C. 192.168.255.255D. 192.168.10.39答案：D.解析：1. 求网络地址/网络ipip与mask：192.168.10.33255.255.255.248-11000000.10101000.00001010.0010000111111111.11111111.11111111.11111000-11000000.10101000.00001010.00100000网络ip2.得出主机位11111111.11111111.111

6、11111.11111000主机位是最后3位3.把主机位全置13个14.网络地址+主机位全为1=广播地址11000000.10101000.00001010.00100111 广播地址192.168.10.394. If you wanted to have 12 subnets with a Class C network ID, which subnet mask would you use?（对一个C类网络，要划分出12个子网，那么，划分后的子网掩码是？）A. 255.255.255.252B. 255.255.255.248C. 255.255.255.240D. 255.255.25

7、5.255答案：C.解析：由题已知这是个C类地址所以2X=12 X=4得出255.255.255.1111所以结果为255.255.255.2405. If you need to have a Class B network address subnetted into exactly 510 subnets, what subnet mask would you assign?（对一个B类网络进行子网划分，要划分出510个子网，则子网掩码是？）A. 255.255.255.252B. 255.255.255.128C. 255.255.255.0D. 255.255.255.192答案：B

8、.解析：由题已知是个B类地址2X=510 X=9所以得出结果为255.255.255.1286. If you are using a Class C network ID with two subnets and need 31 hosts per network, which of the following masks should you use?（对于一个C类网络，要划分出两个子网，每个子网里有31台计算机，则子网掩码是？）A.255.255.255.0B. 255.255.255.192C. 255.255.255.224D. 255.255.255.248答案：B解析：设子网数为

9、X 主机数为Y2X=2 2Y-2=31因为是个C类地址 所以X+Y=8所以X=1 or X=2Y=6 or Y=7所以得出结果为B7. How many subnets and hosts can you get from the network 192.168.254.0/26?（把默认的C类网络划分为192.168.254.0/26，则能获得多少个子网，每子网里有多少主机）A. 4 networks with 64 hostsB. 2 networks with 62 hostsC. 254 networks with 254 hostsD. 1 network with 254 host

10、s答案：B.解析：子网数=26-24=2主机位=32-26=6主机数26-2=62所以答案为B8. You have the network 172.16.10.0/24. How many subnets and hosts are available?（对B类地址进行了划分，划分为172.16.10.0/24，则可用的子网数和主机数是多少？）A. 1 subnet with 10 hostsB. 1 subnet with 254 hostsC. 192 subnets with 10 hostsD. 254 subnets with 254 hosts答案：B.解析：子网位=1主机位为

11、28-2=254所以答案为B9. What mask would you assign to the network ID of 172.16.0.0 if you needed about 100 subnets with about 500 hosts each?（对于172.16.0.0，如果你需要100个子网，每子网500台主机，则掩码是什么？）A. 255.255.255.0B. 255.255.254.0C. 255.255.252.0D. 255.255.0.0答案：B.解析：设子网数为X 主机数为 Y2X=100 2Y-2=500所以X=7 Y=9所以得出255.255.254

12、.010.You have a Class C 192.168.10.0/28 network. How many usable subnets and hosts do you have?（现有一个网络ID192.168.10.0/28，则有多少可用的子网和主机？）A. 16 subnets, 16 hostsB. 14 subnets, 14 hostsC. 30 subnets, 6 hostsD. 62 subnets, 2 hosts答案B.解析：1.因为这是个C类地址，把默认的子网掩码提取出来 242.求借出的的子网位数 subnet X28-24=43.求主机位数 host Y3

13、2-mask=44.求子网和主机数2X=162Y-2=1411. You have the network 192.168.10.0/24. How many subnets and hosts are available?（现在网络ID为192.168.10.0/24，则有多少可用的子网和主机？）A. 1 subnet with 10 hostsB. 1 subnet with 254 hostsC. 192 subnets with 10 hostsD. 254 subnets with 254 hosts答案；B.解析1.因为这是个C类地址，把默认的子网掩码提取出来 242.求借出的的子

14、网位数 subnet X24-24=03.求主机位数 host Y32-mask=84.求子网和主机数2X=128-2=25412. You have a 255.255.255.240 mask. Which two of the following are valid host IDs?（有子网掩码255.255.255.240，则下面哪两个是有效的IP地址？）A. 192.168.10.210B. 192.168.10.32C. 192.168.10.94D. 192.168.10.112E. 192.168.10.127答案：A和C解析：由题可知240=1111 0000 主机号不能全

15、部为0或者全部为1210=1101 001032=0010 000094=0101 1110112=0111 0000127=0111 111113. You have a Class B network ID and need about 450 IP addresses per subnet. What is the best mask for this network?（现在一个B类网络，要对其进行划分，要求每个子网里有450台主机，则最合适的子网掩码是？A. 255.255.240.0B. 255.255.248.0C. 255.255.254.0D. 255.255.255.0答案：

16、C.解析：由题可知B类网络：255.255.xxxxxxxx.xxxxxxxx2X=450X=9所以子网掩码255.255.11111110.0000000所以255.255.254.014. Which of the following is a valid host for network 192.168.10.32/28?（对于网络192.168.10.32/28，下面哪个IP地址是属于此网络的合法IP地址？）A. 192.168.10.39B. 192.168.10.47C. 192.168.10.14D. 192.168.10.54答案：A.由题可知这是个C类地址32的二进制是001

17、00000借位数是四位所以ip的范围00100000-00101111所以合法ip的范围33-4615. What is the valid host range that host 192.168.10.22/30 is a part of?（现有主机的IP地址192.168.10.22/30，那么，这个IP地址属于下面哪个网络？）A. 192.168.10.0B. 192.168.10.16C. 192.168.10.20D. 192.168.0.0答案：C.解析：由题可知这是个C类地址子网掩码为1111110022的二进制是00010110进行与运算得出00010100化成10进制为20所以答案为C