交换与路由基本知识课件.ppt

Emphasize: VTP prunning provides optimized flooding. Without VTP prunning, station A’s broadcast will be flooded to all switches whether they have any port in the red VLAN or not. Note: VLAN1 can’t be prunned. STP, CDP, VTP updates are sent on VLAN1. All switches in the switched network must support prunning or prunning will be disabled. Each trunk port maintains a state variable per VLAN indicating if the switch has any port assigned to a particular VLAN or not. Purpose: This slide discusses the solution of ISL. Emphasize: The Inter-Switch Link (ISL) protocol is used to inter-connect two VLAN-capable Fast Ethernet devices, such as the Catalyst 5000 or Cisco 7500 routers. The ISL protocol is a packet-tagging protocol that contains a standard Ethernet frame and the VLAN information associated with that frame. ISL is currently supported over Fast Ethernet links, but a single ISL link, or trunk, can carry traffic from multiple VLANs. The concept of ISL was discussed in the “Defining Common Workgroups” chapter. How to configure ISL links is discussed later in this chapter. Discuss the example in the SG. Transition: Following is a discussion of ISL links to single router. Purpose: This figure shows the configuration of the router on a stick. Emphasize: Highlight the two different interconnecting networks, and . Purpose: This figure shows the configuration of the router on a stick. Emphasize: Highlight the two different interconnecting networks, and . Purpose: This slide discusses the ping command. Emphasize: Use the ping command to test connectivity to remote hosts. The ping command will return one of the following responses: Success rate is 100 percent or ip address is alive. This response occurs in 1 to 10 seconds, depending on network traffic and the number of ICMP packets sent. Destination does not respond. No answer message is returned if the host does not Unknown host. This response occurs if the targeted host does not exit Destination unreachabl