Check this link out
http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_configuration_guide_chapter09186a00800ca794.html
The basic tasks in the first two sections are required; the tasks in the remaining sections are optional.
⢠Enabling IP Multicast Routing (Required)
⢠Enabling PIM on an Interface (Required)
⢠Configuring Auto-RP (Optional)
⢠IGMP Features Configuration Task List (Optional)
⢠Configuring the TTL Threshold (Optional)
⢠Disabling Fast Switching of IP Multicast (Optional)
⢠SAP Listener Support Configuration Task List (Optional)
⢠Enabling the Functional Address for IP Multicast over Token Ring LANs (Optional)
⢠Configuring PIM Version 2 (Optional)