Something

#include <stdio.h>
#include <windows.h>

int main() {
	//declare variables
	int a, b, c, d;
	printf("enter start range: ");
	scanf("%d.%d.%d.%d",&a,&b,&c,&d);

	//check for a valid range
	if(a>255 || a<0 || b>255 || b<0 || c>255 || c<0 || d>255 || d<0) {
		printf("Invalid Range!\n");
		return 1;
	}

	//increment our ip values
	while(a <= 255)
	{
		while(b <= 255)
		{
			while(c <= 255)
			{
				while(d <= 255)
				{
					printf("%d.%d.%d.%d\n", a, b, c, d);//increment d
					system("cls");
					d++;
				}
				d = 0;
				printf("%d.%d.%d.%d\n", a, b, c, d);//increment c
				system("cls");
				c++;
			}
			c = 0;
			printf("%d.%d.%d.%d\n", a, b, c, d);//increment b
			system("cls");
			b++;
		}
		b = 0;
		printf("%d.%d.%d.%d\n", a, b, c, d);//increment a
		system("cls");
		a++;


	}

	return 0;//normal termination
}