2-3-1-二层交换设备与功能.pptVIP

Emphasize: Layer 2 has no mechanism (like a TTL) to stop loops. Layer 2 of 2 Layer 2 of 2 Layer 3 of 3 Emphasize: Layer 2 has no TTL mechanism to stop looping frames. * Layer 2 of 2 * Layer 2 of 2 * Emphasize: A looped topology is often desired to provide redundancy, but looped traffic is undesirable. The Spanning-Tree protocol was originally designed for bridges. Today, it is also applied to LAN switches and routers operating as a bridge. Spanning-Tree protocol ensures that all bridged segments are reachable but any points where loops occur will be blocked. Layer 3 of 3 Note: 64 bytes is the minimum Ethernet frame size. The command to switch the mode on the 1900 is: wg_sw_a(config)#switching-mode ? fragment-free Fragment Free mode store-and-forward Store-and-Forward mode Purpose: This slide discuss the initial configurations on the routers and switches. Note: There is no setup mode on the Catalyst 1900 switch. Purpose: This slide discuss the initial configurations on the routers and switches. Note: There is no setup mode on the Catalyst 1900 switch. * ? 2007 Cisco Systems, Inc. All rights reserved. ICND2 v1.0—1-* ? 2007 Cisco Systems, Inc. All rights reserved. ICND2 v1.0—1-* Module LAN Configuring Catalyst Switch Operations Basic Layer 2 Switching and Bridging Functions Objectives Upon completing this module, you will be able to: Explain how bridging and switching operates Explain the purpose and operations of the Spanning-Tree Protocol Verify the default configuration of the device, given a functioning access layer switch Build a functional access switch configuration to support the specified network operational parameters, given a network design Execute an add, move, or change on an access layer switch, given a new network requirement Objectives Upon completing this lesson, you will be able to: Describe Layer 2 switching and bridging operations and modes Describe how LAN switches use and populate the MAC address table Address learning Forwa