确定 IPv4 地址的类别、网络和主机 ID 的程序
给定一个字符串形式的有效 IPv4 地址，它遵循全类寻址。任务是确定给定 IPv4 地址的类别，并将网络和主机 ID 部分与其分开。
例子：
Input : 1.4.5.5
Output :
Given IP address belongs to Class A
Network ID is 1
Host ID is 4.5.5
Input : 130.45.151.154
Output :
Given IP address belongs to Class B
Network ID is 130.45
Host ID is 151.154方法
- 确定类别：这个想法是检查 IP 地址的第一个八位字节。我们知道，对于A类，第一个八位字节的范围是1 – 126 ，对于B类，第一个八位字节的范围是128 – 191 ，对于C类，第一个八位字节的范围是192-223 ，对于D类，第一个八位字节的范围是224 – 239 ，对于E类，第一个八位字节的范围为240 – 255 。
- 用于确定网络和主机 ID：我们知道A类的子网掩码是8 ， B类是16 ， C类是24 ，而D类和E类不分为网络和主机 ID。
对于第二个示例，第一个八位字节是 130。因此，它属于B类。 B 类的子网掩码为 16。因此，前 16 位或前两个八位字节是网络 ID 部分，其余的是主机 ID 部分。
因此，网络 ID 为130.45 ，主机 ID 为151.154
C
// C program to determine class, Network
// and Host ID of an IPv4 address
#include
#include
// Function to find out the Class
char findClass(char str[])
{
// storing first octet in arr[] variable
char arr[4];
int i = 0;
while (str[i] != '.')
{
arr[i] = str[i];
i++;
}
i--;
// converting str[] variable into number for
// comparison
int ip = 0, j = 1;
while (i >= 0)
{
ip = ip + (str[i] - '0') * j;
j = j * 10;
i--;
}
// Class A
if (ip >=1 && ip <= 126)
return 'A';
// Class B
else if (ip >= 128 && ip <= 191)
return 'B';
// Class C
else if (ip >= 192 && ip <= 223)
return 'C';
// Class D
else if (ip >= 224 && ip <= 239)
return 'D';
// Class E
else
return 'E';
}
// Function to separate Network ID as well as
// Host ID and print them
void separate(char str[], char ipClass)
{
// Initializing network and host array to NULL
char network[12], host[12];
for (int k = 0; k < 12; k++)
network[k] = host[k] = '\0';
// for class A, only first octet is Network ID
// and rest are Host ID
if (ipClass == 'A')
{
int i = 0, j = 0;
while (str[j] != '.')
network[i++] = str[j++];
i = 0;
j++;
while (str[j] != '\0')
host[i++] = str[j++];
printf("Network ID is %s\n", network);
printf("Host ID is %s\n", host);
}
// for class B, first two octet are Network ID
// and rest are Host ID
else if (ipClass == 'B')
{
int i = 0, j = 0, dotCount = 0;
// storing in network[] up to 2nd dot
// dotCount keeps track of number of
// dots or octets passed
while (dotCount < 2)
{
network[i++] = str[j++];
if (str[j] == '.')
dotCount++;
}
i = 0;
j++;
while (str[j] != '\0')
host[i++] = str[j++];
printf("Network ID is %s\n", network);
printf("Host ID is %s\n", host);
}
// for class C, first three octet are Network ID
// and rest are Host ID
else if (ipClass == 'C')
{
int i = 0, j = 0, dotCount = 0;
// storing in network[] up to 3rd dot
// dotCount keeps track of number of
// dots or octets passed
while (dotCount < 3)
{
network[i++] = str[j++];
if (str[j] == '.')
dotCount++;
}
i = 0;
j++;
while (str[j] != '\0')
host[i++] = str[j++];
printf("Network ID is %s\n", network);
printf("Host ID is %s\n", host);
}
// Class D and E are not divided in Network
// and Host ID
else
printf("In this Class, IP address is not"
" divided into Network and Host ID\n");
}
// Driver function is to test above function
int main()
{
char str[] = "192.226.12.11";
char ipClass = findClass(str);
printf("Given IP address belongs to Class %c\n",
ipClass);
separate(str, ipClass);
return 0;
} Java
// Java program to determine class, Network
// and Host ID of an IPv4 address
class NetworkId{
static String findClass(String str){
// Calculating first occurrence of '.' in str
int index = str.indexOf('.');
// First octate in str in decimal form
String ipsub = str.substring(0,index);
int ip = Integer.parseInt(ipsub);
// Class A
if (ip>=1 && ip<=126)
return "A";
// Class B
else if (ip>=128 && ip<=191)
return "B";
// Class C
else if (ip>=192 && ip<223)
return "C";
// Class D
else if (ip >=224 && ip<=239)
return "D";
// Class E
else
return "E";
}
static void separate(String str, String ipClass){
// Initializing network and host empty
String network = "", host = "";
if(ipClass == "A"){
int index = str.indexOf('.');
network = str.substring(0,index);
host = str.substring(index+1,str.length());
}else if(ipClass == "B"){
//Position of breaking network and HOST id
int index = -1;
int dot = 2;
for(int i=0;iPython3
#function to determine the class of an Ip address
def findClass(ip):
if(ip[0] >= 0 and ip[0] <= 127):
return "A"
else if(ip[0] >=128 and ip[0] <= 191):
return "B"
else if(ip[0] >= 192 and ip[0] <= 223):
return "C"
else if(ip[0] >= 224 and ip[0] <= 239):
return "D"
else:
return "E"
#function to separate network and host id from the given ip address
def seperate(ip, className):
#for class A network
if(className == "A"):
print("Network Address is : ", ip[0])
print("Host Address is : ", ".".join(ip[1:4]))
#for class B network
else if(className == "B"):
print("Network Address is : ", ".".join(ip[0:2]))
print("Host Address is : ", ".".join(ip[2:4]))
#for class C network
else if(className == "C"):
print("Network Address is : ", ".".join(ip[0:3]))
print("Host Address is : ", ip[3])
else:
print("In this Class, IP address is not divided into Network and Host ID")
#driver's code
if __name__ == "__main__":
ip = "192.226.12.11"
ip = ip.split(".")
ip = [int(i) for i in ip]
#getting the network class
networkClass = findClass(ip)
print("Given IP address belongs to class : ", networkClass)
#printing network and host id
ip = [str(i) for i in ip]
separate(ip, networkClass)输出：
Given IP address belongs to Class C
Network ID is 192.226.12
Host ID is 11