I have a multisite installation with quite a lot sites on subdomains. The problem is that all multisite sitemap plugins create a separate sitemap for each site.
I do not want to have to add dozens of sites to Webmasters Tools. This is a lot of work, makes it all hard to manage, and forces me to read all the stats and reports separately, when I want to have only one.
How can I create a single sitemap that encompasses every site in the network?