STP Fast Mode

Configuring Advanced Features

Spanning Tree Protocol (STP)

•Active path from node A to node B: 1—> 3

•Backup (redundant) path from node A to node B: 4 —> 2 —> 3

Configuring Advanced

Features

path cost: 100

switch B

node

switch A

path cost: 100 switch C

path cost:200

path cost: 100

switch D

node

Figure 9-71. Example of Redundant Paths Between Two Nodes

For standard STP operation, when a network connection is established on a device that is running STP, the port used for the connection goes through a sequence of states (Listening and Learning) before getting to its final state (Forwarding or Blocking, as determined by the STP negotiation). This sequence takes two times the forward delay value configured for the switch. The default is 15 seconds on SMC switches, per the IEEE 802.1D standard recommendation, resulting in a total STP negotiation time of 30 seconds. Each switch port goes through this start-up sequence whenever the network con- nection is established on the port. This includes, for example, when the switch or connected device is powered up, or the network cable is connected.

A problem can arise from this long STP start-up sequence because some end nodes are configured to automatically try to access a network server when- ever the end node detects a network connection. Typical server access includes to Novell servers, DHCP servers, and X terminal servers. If the server access is attempted during the time that the switch port is negotiating its STP state, the server access will fail. To provide support for this end node behavior, the SMC6624M offers a configuration mode, called “Fast Mode”, that causes the switch port to skip the standard STP start-up sequence and put the port directly into the “Forwarding” state, thus allowing the server access request to be forwarded when the end node needs it.

If you encounter end nodes that repeatedly indicate server access failure when attempting to bring up their network connection, and you have enabled STP on the switch, try changing the configuration of the switch ports associated with those end nodes to STP Fast Mode.

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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 STP Fast Mode, Example of Redundant Paths Between Two Nodes

Models: SMC6624M