Configuring L2 Multicast Features
805
When a packet with a broadcast or multicast destination MAC address is
received, the switch will flood a copy into each of the remaining network
segments in accordance with the IEEE MAC Bridge standard. Eventually, the
packet is made accessible to all nodes connected to the network.
This approach works well for broadcast packets that are intended to be seen or
processed by all connected nodes. In the case of multicast packets, however,
this approach could lead to less efficient use of network bandwidth,
particularly when the packet is intended for only a small number of nodes.
Packets will be flooded into network segments where no node has any interest
in receiving the packet.
What Is IGMP Snooping?
IGMP snooping allows the switch to snoop on IGMP exchanges between
hosts and multicast routers and perform multicast forwarding within a VLAN.
The IGMP snooping feature complies with RFC 4541. When a switch “sees”
an IGMP report from a host for a given multicast address, the switch adds the
host's interface/VLAN to the L2 multicast group forwarding table and floods
the report to all ports in the VLAN. When the switch sees a leave message for
the group, it removes the host interface/VLAN from the L2 multicast group
forwarding table.
IGMP snooping learns about multicast routers by listening for the following
messages:
• An IGMP query packet.
• PIMv1 (IGMP type 0x14) packets with destination IP address 224.0.0.13.
• DVMRP (IGMP type 0x13) packets with destination IP address 224.0.0.4.
• PIMv2 (IP protocol type 0x67) packets with destination IP address
224.0.0.13.
Group addresses that fall into the range 224.0.0.x are never pruned by IGMP
snooping—they are always flooded to all ports in the VLAN. Note that this
flooding is based on the IP address, not the corresponding 01-00-5e-00-00-xx
MAC address.
When a multicast router is discovered, its interface is added to the interface
distribution list for all multicast groups in the VLAN. If a switch is connected
to a multicast source and no client, the switch filters the traffic from that
group to all interfaces in the VLAN. If the switch sees an IGMP join from a
host in the same VLAN, then it forwards the traffic to the host. Likewise, if
Содержание N2000 Series
Страница 50: ...50 Contents ...
Страница 54: ...54 Introduction ...
Страница 134: ...134 Using Dell OpenManage Switch Administrator ...
Страница 168: ...168 Setting Basic Network Information ...
Страница 206: ...206 Managing a Switch Stack ...
Страница 242: ...242 Configuring Authentication Authorization and Accounting ...
Страница 318: ...318 Managing General System Settings Figure 12 24 Verify MOTD ...
Страница 322: ...322 Managing General System Settings ...
Страница 344: ...344 Configuring SNMP Figure 13 18 Trap Logs Click Clear to delete all entries from the trap log ...
Страница 358: ...358 Configuring SNMP ...
Страница 388: ...388 Managing Images and Files ...
Страница 415: ...Monitoring Switch Traffic 415 Figure 16 2 sFlow Agent Summary ...
Страница 451: ...Monitoring Switch Traffic 451 5 On the Capture Options dialog click Manage Interfaces ...
Страница 458: ...458 Monitoring Switch Traffic ...
Страница 488: ...488 Configuring Port Characteristics Figure 18 3 Copy Port Settings 8 Click Apply ...
Страница 502: ...502 Configuring Port Characteristics ...
Страница 541: ...Configuring Port and System Security 541 Figure 19 12 Configure Port Security Settings 5 Click Apply ...
Страница 567: ...Configuring Port and System Security 567 Figure 19 38 Captive Portal Client Status ...
Страница 666: ...666 Configuring VLANs Figure 21 6 Add Ports to VLAN 4 Click Apply 5 Verify that the ports have been added to the VLAN ...
Страница 674: ...674 Configuring VLANs Figure 21 17 GVRP Port Parameters Table ...
Страница 680: ...680 Configuring VLANs Figure 21 24 Double VLAN Port Parameter Table ...
Страница 714: ...714 Configuring VLANs ...
Страница 737: ...Configuring the Spanning Tree Protocol 737 Figure 22 9 Spanning Tree Global Settings ...
Страница 760: ...760 Configuring the Spanning Tree Protocol ...
Страница 786: ...786 Discovering Network Devices ...
Страница 793: ...Configuring Port Based Traffic Control 793 Figure 24 3 Storm Control 5 Click Apply ...
Страница 878: ...878 Configuring Connectivity Fault Management ...
Страница 899: ...Snooping and Inspecting Traffic 899 Figure 27 17 DAI Interface Configuration Summary ...
Страница 903: ...Snooping and Inspecting Traffic 903 Figure 27 24 Dynamic ARP Inspection Statistics ...
Страница 924: ...924 Configuring Link Aggregation Figure 28 7 LAG Hash Summary ...
Страница 982: ...982 Configuring Link Aggregation ...
Страница 1062: ...1062 Configuring DHCP Server and Relay Settings ...
Страница 1096: ...1096 Configuring L2 and L3 Relay Features Figure 34 3 DHCP Relay Interface Summary ...
Страница 1200: ...1200 Configuring OSPF and OSPFv3 ...
Страница 1216: ...1216 Configuring RIP ...
Страница 1240: ...1240 Configuring VRRP ...
Страница 1284: ...1284 Configuring DHCPv6 Server and Relay Settings Relay Interface Number Vl100 Relay Remote ID Option Flags ...
Страница 1291: ...Configuring Differentiated Services 1291 Figure 40 5 DiffServ Class Criteria ...
Страница 1336: ...1336 Configuring Auto VoIP ...
Страница 1367: ...Managing IPv4 and IPv6 Multicast 1367 Figure 43 20 IGMP Cache Information ...
Страница 1422: ...1422 Managing IPv4 and IPv6 Multicast ...
Страница 1440: ...1440 System Process Definitions ...
Страница 1460: ...Index 1460 ...