Netgear M4300-24X (XSM4324CS) - Stackable Switches with Full PoE+ Provisioning 管理者ガイド
DVMRP
641
Managed Switches
Distance Vector Multicast Routing Protocol Concepts
The Distance Vector Multicast Routing Protocol (DVMRP) is used for multicasting over IP
networks without routing protocols to support multicast. The DVMRP is based on the RIP
protocol but more complicated than RIP. DVRMP maintains a link-state database to keep
track of the return paths to the source of multicast packages.
networks without routing protocols to support multicast. The DVMRP is based on the RIP
protocol but more complicated than RIP. DVRMP maintains a link-state database to keep
track of the return paths to the source of multicast packages.
The DVMRP operates as follows:
•
The first message for any source-group pair is forwarded to the entire multicast network,
with respect to the time-to-live (TTL) of the packet.
with respect to the time-to-live (TTL) of the packet.
•
TTL restricts the area to be flooded by the message.
•
All the leaf routers that do not have members on directly attached subnetworks send back
prune messages to the upstream router.
•
The branch that transmitted a prune message is deleted from the delivery tree.
•
The delivery tree, which is spanning to all the members in the multicast group, is
constructed.
constructed.
In this example, DVMRP is running on switches A, B, and C. IGMP is also running on
Switch C, which is connected to the host directly. After the host sends an IGMP report to
switch C, multicast streams are sent from the multicast resource to the host along the path
built by DVMRP.
Switch C, which is connected to the host directly. After the host sends an IGMP report to
switch C, multicast streams are sent from the multicast resource to the host along the path
built by DVMRP.
Figure 62. DVMRP
192.168.1.0/24
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192.168.5.0/24
192.168.3.0/24
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1/0/3
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192.168.4.0/24
192.168.4.0/24
Switch A
Switch C
Switch B
Host
Multicast
resource
resource
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