136 2 0 0 0 - A 2 - G B 2 3 - 0 03 Type “E” to enable PIM on this port, or type D to disable it. The IAD savesthe new configuration and displays the Multicast Configuration menu.Add/Change Multicast Route SourceReverse Path Forwarding (RPF) checks the IP address of the sender of thepacket and then finds the best outgoing interface from its normal IP routingtable.Type “S” on the Multicast Configuration menu to add or change theMulticast Route Source. The IAD displays the Multicast Routing Sourcemenu:Figure 4.101Multicast Routing Source MenuAdding a MulticastRouting Source1 Type “A” on the Multicast Routing Source menu to add a MulticastRouting Source. The IAD creates a multicast routing source and adds it tothe Multicast Routing Source Table. The IAD prompts you to enter and IPaddress for the Source.2 Type the Source IP address and press Enter. The IAD displays the currentsubnet mask and prompts you to enter a new one.3 Type the new subnet address and press Enter. The IAD displays theavailable interfaces and prompts you to select one as shown in Figure 4.33.4 Type the option number to select the interface. The IAD displays the porttable for this interface and prompts you to select a port.5 Type the port to configure and press Enter. The IAD saves the newconfiguration and displays the Multicast Configuration menu.Remove a MulticastRouting SourceTo remove a Multicast Routing Source, follow the steps below.1 Type “R” on the Multicast Routing Source menu. The IAD prompts you toenter an IP address for the Source.2 Type the source IP address and press Enter. The IAD displays the currentsubnet mask and prompts you to enter a new one.3 Type the new subnet address and press Enter. The IAD displays theavailable interfaces and prompts you to select one as shown in Figure 4.33.4 Type the option number to select the interface. The IAD displays the porttable (sample shown above) for this interface and prompts you to select aport.