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| Title | Size | Download |
|---|---|---|
| 02-Common Multicast Configuration | 43.51 KB |
Chapter 1 Common Multicast Configuration
1.1 Introduction to Common Multicast Configuration
1.2 Common Multicast Configuration
1.2.1 Enabling Multicast Routing
1.2.2 Configuring the Capacity Threshold for a Multicast Routing Table
1.2.3 Clearing MFC Forwarding Entries or Its Statistic Information
1.2.4 Clearing Route Entries from the Core Multicast Routing Table
1.2.5 Configuring Broadcast/Multicast Suppression
1.3 Displaying and Maintaining Common Multicast Configuration
Chapter 1 Common Multicast Configuration
1.1 Introduction to Common Multicast Configuration
The multicast common configuration is for both the multicast group management protocol and the multicast routing protocol. The configuration includes enabling IP multicast routing, displaying multicast routing table and multicast forwarding table, etc.
1.2 Common Multicast Configuration
Common multicast configuration includes:
l Configuring the Capacity Threshold for a Multicast Routing Table
l Clearing MFC Forwarding Entries or Its Statistic Information
l Clearing Route Entries from the Core Multicast Routing Table
l Configuring Broadcast/Multicast Suppression
1.2.1 Enabling Multicast Routing
You must enable Layer 3 multicast routing in system view before configuring a multicast routing protocol.
Perform the following configuration in system view to enable/disable multicast routing:
|
To do... |
Use the command... |
|
Enable multicast routing |
multicast routing-enable |
|
Disable multicast routing |
undo multicast routing-enable |
By default, multicast routing is disabled.
Caution:
Multicast routing must be enabled before other Layer 3 multicast configurations can take effect.
1.2.2 Configuring the Capacity Threshold for a Multicast Routing Table
Follow these steps to configure the capacity threshold for a multicast routing table:
|
To do... |
Use the command... |
Remarks |
|
Enter system view |
system-view |
— |
|
Set the capacity threshold for a multicast routing table |
multicast route-limit limit |
By default, the capacity threshold for a multicast routing table is 512. |
& Note:
l A newly inserted interface board will not work if it does not support the current system configuration on multicast routing table capacity.
l When the command is used repeatedly, the latest configuration will overwrite the previous configuration.
Caution:
While configuring the capacity threshold for a multicast routing table, be aware of the following aspects:
l If the new threshold setting is smaller than the current capacity of a multicast routing table, the system will prompt: “Modifying the limit will delete all multicast routing tables. Do you want to continue? [Y/N] Y”. If the user types “Y”, all the entries in the current multicast routing table will be deleted and the new capacity threshold will take effect.
l If the new threshold setting is greater than the current capacity for a multicast routing table, and the system has an interface board that does not support the threshold setting, the system will prompt: “Slot X does not support the limit, configuration failed”. Otherwise, the new capacity threshold can be configured successfully.
1.2.3 Clearing MFC Forwarding Entries or Its Statistic Information
Perform the following configuration in user view to clear MFC forwarding entries or its statistic information:
|
To do... |
Use the command... |
|
Clear MFC forwarding entries or its statistic information |
reset multicast forwarding-table [ statistics ] { all | { group-address [ mask { group-mask | group-mask-length } ] | source-address [ mask { source-mask | source-mask-length } ] | incoming-interface { null null-interface-number | interface-type interface-number } } * } |
1.2.4 Clearing Route Entries from the Core Multicast Routing Table
Perform the following configuration in user view to clear route entries from the core multicast routing table:
|
To do... |
Use the command... |
|
Clear route entries from the core multicast routing table |
reset multicast routing-table { all | { group-address [ mask { group-mask | group-mask-length } ] | source-address [ mask { source-mask | source-mask-length } ] | incoming-interface vlan-interface interface-number } * } |
The corresponding MFC forwarding entries are cleared when routing entries are cleared from the core multicast routing table.
1.2.5 Configuring Broadcast/Multicast Suppression
To prevent port congestion resulting from broadcast/multicast packet flooding, the switch supports broadcast/multicast suppression. You can enable broadcast/multicast suppression by setting the speed percentage or bandwidth values.
Follow these steps to configure broadcast/multicast suppression:
|
To do... |
Use the command... |
Remarks |
|
Enter system view |
system-view |
— |
|
Enter Ethernet port view |
interface interface-type interface-number |
Required interface-type is Ethernet or GigabitEthernet. |
|
Configure multicast suppression ration Ethernet port |
multicast-suppression { ratio | bandwidth bandwidth } |
Optional By default, the multicast suppression ratio is 100% The bandwidth argument is in Mbps. |
|
Configure broadcast suppression ration Ethernet port |
broadcast-suppression { ratio | bandwidth bandwidth } |
Optional By default, the broadcast suppression ratio is 50% The bandwidth argument is in Mbps. |
Caution:
l You cannot enable both broadcast suppression and multicast suppression simultaneously on the same card (broadcast suppression is enabled by default). Namely, once you have enabled broadcast suppression on some ports of a card, you cannot enable multicast suppression on the other ports of the card, and vice versa.
l If multicast suppression is enabled, broadcast packets are also suppressed at the same time, while broadcast suppression does not work on multicast suppression.
l No distinction is made between known multicast and unknown multicast for multicast suppression.
1.3 Displaying and Maintaining Common Multicast Configuration
|
To do... |
Use the command... |
Remarks |
|
Display the multicast routing table |
display multicast routing-table [ group-address [ mask { mask | mask-length } ] | source-address [ mask { mask | mask-length } ] | incoming-interface { vlan-interface vlan-interface-number | register } ] * |
Available in any view |
|
Display the multicast forwarding table |
display multicast forwarding-table [ group-address [ mask { mask | mask-length } ] | source-address [ mask { mask | mask-length } ] | incoming-interface { interface-type interface-number | null null-interface-number | register } ] * |
Available in any view |
|
Display port-specific multicast forwarding table |
display mpm forwarding-table [ group-address | source-address ] |
Available in any view |
|
Display information about the IP multicast groups or MAC multicast groups in a specified VLAN or all VLANs. |
display mpm group [ vlan vlan-id [ ip-address ] ] |
Available in any view |
|
Enable multicast packet forwarding debugging |
debugging multicast forwarding |
Available in user view |
|
Disable multicast packet forwarding debugging |
undo debugging multicast forwarding |
Available in user view |
|
Enable multicast forwarding status debugging |
debugging multicast status-forwarding |
Available in user view |
|
Disable multicast forwarding status debugging |
undo debugging multicast status-forwarding |
Available in user view |
|
Enable core multicast routing debugging |
debugging multicast kernel-routing |
Available in user view |
|
Disable core multicast routing debugging |
undo debugging multicast kernel-routing |
Available in user view |
The multicast routing tables can be layered as follows:
l Each multicast routing protocol has a multicast routing table of itself.
l All the multicast routing tables can be summarized into the core multicast routing tables.
l The core multicast routing tables should keep consistent with the multicast forwarding tables which actually control the forwarding of the multicast data packets.
The multicast forwarding tables are mainly used for debugging. Usually, users can view the core multicast routing tables to get the required information.
