how to calculate subnet mask from ip address

In Oracle, IP addresses and masks are converted to the CIDR format due to the following problems: IP addresses and IP address masks are stored in the database and must be converted to the CIDR format, in addition, it is not only about converting the mask into a number corres

Obtain the local IP address, mask, and gateway in Linux. 1. Obtain the local IP address and mask /******************************** ************************************* Functi

IPY module originally used to enter the correct network bit and mask, I use the mechanism of processing error to achieve the input of any IP address and mask can correctly output the results of small programs.1 #!/usr/bin/env python2 #-*-coding:utf-8-*-3 #@Date: 2017-09-04 21:57:154 #@Author: Enderzhou ([email protecte

In the Aliyun background of cloud shield monitoring---"threat---" attack, will find a large number of malicious attacks every day, there are a large number of GET requests, resulting in server resources waste useless consumption. Type of attack in the last 7 days Carefully look at the source of the attack information, found that more than 99% of the attack IP address, there are historical att

This article describes the C + + acquisition of the local Mac,ip,mask address method, shared for everyone to reference. The specific methods are as follows: Copy Code code as follows: #include "InitSock.h" #include #include #pragma comment (lib, "IPHLPAPI.lib") U_char G_uclocalmac[6]; DWORD G_dwgatewayip; DWORD G_dwlocalip; DWORD G_dwmask;

. Also use MySQL's function Inet_aton (' 119.115.0.0 ') to derive an integer. In addition MySQL database field set four fields, starting IP, terminating IP, starting IP integer, terminating IP integer, How to calculate an IP

#include #include #include #include #include #include #include #include int setifaddr (char *ifname, Char *ipaddr, char *mask,char *gateway){int fd;int RC;struct ifreq IFR;struct sockaddr_in *sin;struct Rtentry RT; FD = socket (af_inet, SOCK_DGRAM, 0);if (FD {perror ("socket error"); return-1; }memset (ifr,0,sizeof (IFR));strcpy (ifr.ifr_name,ifname);sin = (struct sockaddr_in*) ifr.ifr_addr; sin->sin_family = af_inet; //ipaddrif (Inet_aton (ipaddr,

/*Create table 'db _ online '('IP' char (20) default NULL,'Time' char (20) not null default '','Name' char (200) not null default 'tourists') TYPE = MyISAM*/// Roughly calculate the online time. If the ip address is the same (Lan> external network), only one person is recorded. However, there are few chances.Session_st

/* Create Table 'db _ online '('IP' char (20) default null,'Time' char (20) not null default '','Name' char (200) not null default 'tourists') Type = MyISAM */ // Roughly calculate the online time. If the IP address is the same (Lan> external network), only one person is recorded. However, there are few chances.