D-Link DGS-3630 User Manual 1 - Page 329

DGS-3630 Series Layer 3 Stackable Managed Switch Web UI Reference Guide The PIM-DM multicast routing protocol is assumes that all downstream routers want to receive multicast messages and relies upon explicit prune messages from downstream routers to remove branches from the multicast delivery tree that do not contain multicast group members. PIM-DM has no explicit Join messages. It relies upon periodic flooding of multicast messages to all interfaces and then either waiting for a timer to expire (the Join/Prune Interval), or for the downstream routers to transmit explicit Prune messages indicating that there are no multicast members on their respective branches. PIM-DM then removes these branches (Prunes them) from the multicast delivery tree. As a member of a pruned branch of a multicast delivery tree may want to join a multicast delivery group (at some point in the future), the protocol periodically removes the 'prune' information from its database and floods multicast messages to all interfaces on that branch. The interval for removing 'prune' information is the Join/Prune Interval. PIM-SM-DM In the PIM-SM, RP is a key point for the first hop of the sender. If the first hop does not have RP information when the sender sends information out, it will drop the packet and do nothing. Sparse-Dense mode will be useful in this condition. In Sparse-Dense mode, the packets can be flooded to all the outgoing interfaces and pruning/joining (Prune/Graft) can be used to control the outgoing interface list if RP is not found. In other words, the PIM SparseDense mode is treated in either the sparse mode or dense mode of the operation; it depends on which mode the multicast group operates. When an interface receives multicast traffic, if there is a known RP for the group, then the current operation mode on the interface is sparse mode, otherwise the current operation mode on the interface will be dense mode. PIM for IPv4 PIM Interface This window is used to display and configure the Protocol Independent Multicast (PIM) interface settings. To view the following window, click L3 Features > IP Multicast Routing Protocol > PIM > PIM for IPv4 > PIM Interface, as shown below: Figure 6-109 PIM Interface Window The fields that can be configured are described below: Parameter Interface Name Mode Description Select and enter the name of the interface here. Select the operation mode of PIM entries used in this filtered search here. Options to choose from are Dense Mode, Sparse Mode, and Sparse-Dense Mode. Click the Find button to locate a specific entry based on the information entered. Click the Show All button to display all the entries. Click the Edit button to modify the specified entry. Enter a page number and click the Go button to navigate to a specific page when multiple pages exist. 317