public static boolean isUnspecifiedAddress(final String ipAddress) {
    return INADDR_ANY.equals(ipAddress)
        || INADDR6_ANY.equals(ipAddress)
        || INADDR_NONE.equals(ipAddress)
        || INADDR6_NONE.equals(ipAddress);
  }
Is unspecified address.

@param ipAddress the ip address
@return the boolean
util/src/main/java/org/hyperledger/besu/util/NetworkUtility.java