cisco ccna 200-301 training

cisco ccna 200-301 training.Finally, the end of this example shows that when restricted mode is used, the switch generates a log message for each violation. You can see this message from the console, or the remote user has entered the terminal monitor EXEC command, or you can see the message from Telnet or Secure Shell (SSH). By checking the end of the show interfaces trunk command of each switch, it can be found that among the two trunk interfaces of each switch, only the GiO/2 interface of SW2 is not currently forwarding the communication of VLAN3. The previous section 3.2.2.5 of this chapter lists 4 reasons why VLANs are excluded from trunking. However, based on the command output in Example 3-14 and several other examples in this chapter, three reasons can be ruled out. First, if VLAN3 is excluded, it may be because VLAN3 is not in the list of allowed VLANs, or because VLAN3 is not in the active state, but from the first two lines of the output of the show interfaces trunk command of SW2, we can see that VLAN3 is not ignored, so The above two possibilities can be ruled out. Moreover, VTP pruning can also be ruled out, because the previous example shows that all three switches have at least one interface in VLAN3 and are in a connected state. In this way, even if all switches use VTP correctly and VTP pruning is enabled, VLAN3 is still Will not be trimmed. Therefore, in this case, it is only possible that STP caused VLAN3 to be ignored.