Role of the Switch

Configuring Advanced Features

Multimedia Traffic Control with IP Multicast (IGMP)

to or from the same source(s) is termed a multicast group, and all devices in the group use the same multicast group address. The multicast group running version 2 of IGMP uses three fundamental types of messages to communicate:

■Query: A message sent from the querier (multicast router or switch) asking for a response from each host belonging to the multicast group. If a multicast router supporting IGMP is not present, then the switch must assume this function in order to elicit group membership information from the hosts on the network. (If you need to disable the querier feature, you can do so through the CLI, using the IGMP configuration MIB. See “Changing the Querier Configuration Setting” on page “Configuring the Querier Function” on page 9-94.)

■Report: A message sent by a host to the querier to indicate that the host wants to be or is a member of a given group indicated in the report message.

■Leave Group: A message sent by a host to the querier to indicate that the host has ceased to be a member of a specific multicast group.

Thus, IGMP identifies members of a multicast group (within a subnet) and allows IGMP-configured hosts (and routers) to join or leave multicast groups.

IGMP Data. To display data showing active group addresses, reports, que- ries, querier access port, and active group address data (port, type, and access), see “IP Multicast (IGMP) Status” on page 10-16.

When IGMP is enabled on the switch, it examines the IGMP packets it receives:

■To learn which of its ports are linked to IGMP hosts and multicast routers/ queriers belonging to any multicast group

■To become a querier if a multicast router/querier is not discovered on the network

Once the switch learns the port location of the hosts belonging to any partic- ular multicast group, it can direct group traffic to only those ports, resulting in bandwidth savings on ports where group members do not reside. The following example illustrates this operation.

Figure 9-67on page 9-96shows a network running IGMP.

■PCs 1 and 4, switch 2, and all of the routers are members of an IP multicast group. (The routers operate as queriers.)

■Switch 1 ignores IGMP traffic and does not distinguish between IP multi- cast group members and non-members. Thus, it is sending large amounts of unwanted multicast traffic out the ports to PCs 2 and 3.

Features	Configuring Advanced

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SMC6624M specifications

SMC Networks SMC6624M is a robust and versatile managed switch designed to meet the needs of enterprises seeking reliable network solutions. This device features 24 Gigabit Ethernet ports that allow for high-speed data transfer, making it ideal for environments that demand high bandwidth. The SMC6624M is particularly suited for small to medium-sized businesses that require a powerful network backbone to support various applications, including voice, video, and data transmission.

One of the standout features of the SMC6624M is its Layer 2 and Layer 3 switching capabilities, enhancing the flexibility and efficiency of network management. The switch supports VLANs (Virtual Local Area Networks), which allow administrators to segment network traffic for improved security and performance. This capability is essential for organizations looking to optimize their network resources and apply policies that enhance security.

The SMC6624M also integrates advanced Quality of Service (QoS) features, enabling the prioritization of network traffic. This is particularly useful for applications such as VoIP and video conferencing, where maintaining low latency and jitter is crucial for ensuring a seamless user experience. Users can define traffic classes and manage bandwidth allocation, which helps in maintaining the quality of critical applications even during peak usage times.

In terms of connectivity and performance, the SMC6624M includes 4 Gigabit SFP ports, allowing for fiber optic connections to extend network reach and provide flexibility in deployment. The ability to take advantage of high-speed fiber connections means businesses can scale their networks as needed without significant infrastructure changes.

Management options for the SMC6624M are comprehensive. It supports SNMP (Simple Network Management Protocol) for monitoring and managing network performance effectively. Additionally, the switch can be configured using a web-based interface, command-line interface (CLI), or through SNMP, providing flexibility to network administrators with different preferences and expertise.

Furthermore, the SMC6624M is built with a fanless design, which ensures quiet operation and is energy efficient. Its compact form factor and sturdy build make it suitable for installation in various environments, including data centers and office settings.

Overall, the SMC Networks SMC6624M stands out for its combination of speed, flexibility, and management features, making it an excellent choice for businesses looking to enhance their network infrastructure. With a focus on reliability and performance, this managed switch promises to deliver the capabilities that today's modern networks demand.

SMC Networks SMC6624M manual Role of the Switch

Models: SMC6624M

Configuring Advanced Features

Multimedia Traffic Control with IP Multicast (IGMP)