public void testAllPairs(File file){
	try {
	    Scanner scan = new Scanner(file);
	    while(scan.hasNextLine()){
		String[] line = scan.nextLine().split("\t");
		if(line.length != 2)
		    continue;
		int ip = stringToIP(line[0].trim());
		String host = line[1].trim();
		if(!testPair(ip, host)){
		    System.out.println("Missing: " + IPToString(ip) + " -> " + host);
		}
		if(!testPair(host, ip)){
		    System.out.println("Missing: " + host + " -> " + IPToString(ip));
		}
	    }
	    scan.close();
	} catch (FileNotFoundException e) {
	    e.printStackTrace();
	}
    }