1. Question: Configuring login local does not have a username and password configured Answer: it will cause the device to fail to log on especially ten configured line console 0. At this time, it can only do password recovery. 2. Question: Line cons

1. Question: The meaning of the dot 1 q tunnel interface's untag and tag Answer: Untag refers to the use of the untag vlan tag and forwarded when you want to send a data frame. Tag means to keep the original vlan tag and forward it. 2. Question: Mat

1. Question: When the port appears CRC, drop, error, oversized. Answer: Physical replacement test that to determine if there is a problem at the physical level, you can also check whether the mtu value is too small and whether there is a vlan tailored.

1. Question: The interface is turned on authentication and it can see the mac address learned on the interface by showing mac before authentication. If the interface's device is authenticated , dose show mac can't see the device? Answer: This can be re

1. Question: Does ip source guard cause cpu to rise? Answer: No, ip source guard is hardware-based, and filtering the ip message smac plus ip that does not conform to the dhcp snooping table item does not cause cpu to rise. 2. Question: What is the

1. Question: Why does the SVI interface down use ACL that cannot take effect? Answer: (1) Check ACL configuration (2) Confirm the direction of the ACL call (3) Confirm whether the physical interface for data communication has invoked the ACL rule

1. Question: What will the port security interface do if it is configured with the switchport port-security shutdown command? Answer: The interface is automatically closed and the interface state is disable. 2. Question: What forms of port security

1. Question: STP View Command: What does the meaning of the p2p and shar of type respectively? Answer: Type field and link capability related, directly connected are p2p, half duplex automatically recognized as shar. 2. Question: What does a NAK mes

1. Question: Is the switch docking virtual machine unreachable? Answer: The data sent by the VM cluster may be a vlan tag. The interface of the switch is configured with a trunk and the corresponding vlan is created. 2. Question: Under the interface