If you are finding that no federated search results are displayed in searches, or you see a Location not found error message, a server proxy setting is most likely stopping the crawler from reaching a federated search location. You can specify proxy server settings for crawling content and querying federated sources on computers in other networks, such as the Internet. In many cases it is necessary to use a proxy server to bypass intranet security restrictions.
Verify that the user account that is performing this procedure is an administrator for the search service application.
In Central Administration, in the Quick Launch, click General Application Settings.
On the General Application Settings page, in the Search section, click Farm Search Administration.
On the Farm Search Administration page, in the Farm-Level Search Settings section, click the value of the Proxy server setting.
In the Search Proxy Setting dialog box, select Do not connect by using a proxy server if you do not want the crawler to use a proxy server. Select Use the proxy server specified if you want the crawler to use a proxy server when crawling content. If you select this option, configure the following options:
Click OK.