D-Link DGS-3324SR Product Manual - Page 220

Assert Messages, PIM-DM Interface Configuration, PIM Global Settings, PIM Interface Settings

Page 220 highlights

xStack DGS/DXS-3300 Series Layer 3 Stackable Gigabit Ethernet Switch User Manual When the latter occurs, the same packet may be sent twice, one type encapsulated, one not. The RP will detect this flaw and then return a Register Suppression message to the DR requesting it to discontinue sending encapsulated packets. Assert Messages At times on the PIM-SM enabled network, parallel paths are created from source to receiver, meaning some receivers will receive the same multicast packets twice. To improve this situation, Assert messages are sent from the receiving device to both multicast sources to determine which single router will send the receiver the necessary multicast data. The source with the shortest metric (hop count) will be elected as the primary multicast source. This metric value is included within the Assert message. PIM-DM Interface Configuration The Protocol Independent Multicast - Dense Mode (PIM-DM) protocol should be used in networks with a low delay (low latency) and high bandwidth as PIM-DM is optimized to guarantee delivery of multicast packets, not to reduce overhead. 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. Because 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 Global Settings To enable PIM globally on the Switch, go to Configuration > Layer 3 IP Networking > IP Multicast Routing Protocol > PIM Protocol > PIM Global Settings. This will give the user access to the following screen: Figure 6- 168. PIM Global Settings window Use the pull-down menu, choose Enabled, and click Apply to set the PIM function on the Switch. PIM Interface Settings To configure the settings for the PIM Protocol per IP interface, go to Configuration > Layer 3 IP Networking > IP Multicast Routing Protocol > PIM Protocol > PIM Interface Settings. This will give the user access to the following screen: Figure 6- 169. PIM Interface Settings window To configure an IP interface for PIM, click its corresponding link which will lead you to the following screen: 205

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xStack DGS/DXS-3300 Series Layer 3 Stackable Gigabit Ethernet Switch User Manual
205
When the latter occurs, the same packet may be sent twice, one type encapsulated, one not. The RP will detect this flaw
and then return a Register Suppression message to the DR requesting it to discontinue sending encapsulated packets.
Assert Messages
At times on the PIM-SM enabled network, parallel paths are created from source to receiver, meaning some receivers will
receive the same multicast packets twice. To improve this situation, Assert messages are sent from the receiving device to
both multicast sources to determine which single router will send the receiver the necessary multicast data. The source with
the shortest metric (hop count) will be elected as the primary multicast source. This metric value is included within the
Assert message.
PIM-DM Interface Configuration
The
Protocol Independent Multicast - Dense Mode
(PIM-DM) protocol should be used in networks with a low delay (low
latency) and high bandwidth as PIM-DM is optimized to guarantee delivery of multicast packets, not to reduce overhead.
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.
Because 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 Global Settings
To enable PIM globally on the Switch, go to
Configuration > Layer 3 IP Networking > IP Multicast Routing Protocol
> PIM Protocol > PIM Global Settings
. This will give the user access to the following screen:
Figure 6- 168. PIM Global Settings window
Use the pull-down menu, choose
Enabled
, and click
Apply
to set the PIM function on the Switch.
PIM Interface Settings
To configure the settings for the PIM Protocol per IP interface, go to
Configuration > Layer 3 IP Networking > IP
Multicast Routing Protocol > PIM Protocol > PIM Interface Settings
. This will give the user access to the following
screen:
Figure 6- 169. PIM Interface Settings window
To configure an IP interface for PIM, click its corresponding link which will lead you to the following screen: