public static HashMap<String, String> getAllIPAndMACAddressesInARPCache() {
        HashMap<String, String> macList = getAllIPandMACAddressesFromIPSleigh();
        for (String line : getLinesInARPCache()) {
            String[] splitted = line.split(" +");
            if (splitted.length >= 4) {
                // Ignore values with invalid MAC addresses
                if (splitted[3].matches("..:..:..:..:..:..")
                        && !splitted[3].equals("00:00:00:00:00:00")) {
                    if (!macList.containsKey(splitted[0])) {
                        macList.put(splitted[0], splitted[3]);
                    }
                }
            }
        }
        return macList;
    }
Returns all the IP/MAC address pairs currently in the following places

1. ARP cache (/proc/net/arp).
2. `ip neigh show` command

@return list of IP/MAC address pairs found
library/src/main/java/com/stealthcopter/networktools/ARPInfo.java