click here
http://www.interactivewebs.com/blog/index.php/server-tips/microsoft-crm-2011-how-to-configure-ifd-hosted-setup/
http://www.interactivewebs.com/blog/index.php/server-tips/microsoft-crm-2011-how-to-configure-ifd-hosted-setup/
steps to configure IFD for CRM on premise
.Download the Microsoft Dynamics CRM 2011 Implementation Guide (click here) - Follow instructions in section "Configure Microsoft Dynamics CRM for Internet-facing deployment" to set up an IFD environmentDownload the Microsoft Dynamics IFD configuration tool from: http://support.microsoft.com/kb/948779
Instruct your network administrator to add the following IP range (64.56.203.0-64.56.203.255) to allow access your network
Instruct your network administrator to configure the external DNS to allow https://your.dynamicsurl.com to resolve from outside the firewall
Wait 4-6 hours to allow time for DNS replication to complete