Redactor pagebreak plugin and linking to pages
The example is the docs you're referring to will simple output the first "page" of the Rich Text field and if there are more pages show a "Continue Reading" link that loads the full entry.

For the functionality you're looking for you'd have to do something like this (completely untested):

{% set totalPages = entry.body.getTotalPages() %}

{% for i in 1..totalPages %}
    &lt;a href="{{ url(entry.url, {page: i}) }}"&gt;{{ i }}&lt;/a&gt;
{% endfor %}


Then your template would grab the page from the querystring and display it  using entry.body.getPage(page).