ccna zertifizierung

ccna zertifizierung.. the BPDU is used to elect the root switch as well as to share topology information. . the BPDUs are multicast with an announcement interval of 2 seconds.. There are five STP port states: blocking (processing BPDUs only, for 20 seconds), listening (processing BPDUs only, for 15 seconds), learning (processing BPDUs and creating CAM tables, for 15 seconds), forwarding (processing BPDUs, creating CAM tables, and forwarding user traffic), and disabled (port not enabled). The root port and the designated port will eventually enter the forwarding phase, but it takes 30.50 seconds to do so..PortFast allows the port to remain in the forwarding state during STP recalculation; this feature should not be used for connections between switches to avoid inadvertently causing loops..PVST+ is Cisco-specific and lets each VLAN use a separate instance of STP.Fast Spanning Tree Protocol. There are three RSTP port states: dropped, learned, and forwarded. . two new port types have been added to RSTP: alternative port (secondary root port) and alternate port (secondary designated port) 0.EtherChannel is a Layer 2 physical connection grouping between devices, but appears to STP as a logical connection.All ports contained in the EtherChannel must be configured identically; to establish the channel, either PAgP or LACP can be used.STP Troubleshooting. One symptom of a broadcast storm is high CPU and port usage. . To determine if a loop exists, use the protocol analyzer to find multiple copies of the same frame.