How to parse ip string

That's the correct behaviour of the stringstream's extraction operator: you requested an int and it provided the first valid int represented in the string.
If you want to extract the four ip octects as integers then try the following code:

#include <iostream>
#include <sstream>
#include <string>
using namespace std;
int main()
{
  string ip;
  int anwswer;
  int octet[4];
  char c;

  do
  {
    cout << "Enter IPv4: ";
    getline (cin,ip);
    stringstream s(ip);
    for (int n=0; n<4; ++n)
      s >> octet[n] >> c;

    for (int n=0; n<4; ++n)
      cout << "octet[" << n << "]=" << octet[n] << endl;

    cin>>c;
    if(c == 'y')
      cout<<"DONE!"; //place in to batch file
    else
      cout<<"NOT DONE!"; /
  } while (c != 'y');

  return 0;
}