I followed the directions in the Membership Providers document provided by Sitecore, but I was unable to get my membership provider to work correctly.
Specifically, in the web.config, I changed the "realProviderName" attribute on the sitecore provider to point to my provider. However, this didn't do anything.
I realized that the "defaultProvider" attribute was set to the "switcher" provider, so I changed that to point directly at my provider, and it worked, but I'm not sure if I'm causing problems elsewhere by doing this...
Has anyone done this before?
I think what you probably want to do is set the defaultProvider="sitecore" then on the provider named sitecore change the realProviderName to be the name of your custom provider. The switcher is used if you want to house a certain domain (i.e. extranet) in a different membership database.
I found that the example Sitecore gives in their docs for this does indeed work.