Missing Page Editing Toolbar? Breadcrumb Links Wrong?

If a SharePoint site is being accessed through a router or a proxy server, a missing Alternate Access Mapping (AAM) setting can cause all sorts of strange and seemingly unrelated issues. Here are a few symptoms that I experienced recently when viewing a SharePoint publishing site exposed through a router:

• The Page Editing toolbar was missing on publishing pages. The toolbar did not display when the "Edit Page" option was selected on the site actions button
• The "Show Page Editing Toolbar" option was greyed out (disabled) in the Site Actions menu
• The links to the site home page in the breadcrumb trail and from the tab in the top navigation bar failed to open a page (page not found)

These were all caused by the fact that the URL used to request the pages through the router differed from the URL passed to the SharePoint server by the router. And that is the purpose of the Alternate Access Mappings. Adding the appropriate AAM values cured the problems, and also improved the rendering speed of pages in the site.

For more on AAM, see the excellent series of articles named "What every SharePoint administrator needs to know about Alternate Access Mappings" on the Microsoft SharePoint Team Blog:

1. Part 1
2. Part 2
3. Part 3