Method step
1. First, connect the switch through the CONSOLO port or telnet to enter the user mode? "
2. Input in user mode? Hmm? , enter privileged mode? Sw#？
3. Input in privileged mode? conf t？ , enter the global mode? Software (Configuration) #
4. Next, enter the interface mode in global mode, and enter? Int range f0/ 1-3? It should be noted here that the range parameter can be used to enter multiple interfaces. Three interfaces are selected here, f0/ 1, f0/2 and f0/3.
5. Then add these three interfaces together to VLAN 20. In the interface mode, enter? No switch port is connected to vlan 20?
6. Finally, we use? Show run "Looking at the switch configuration, you can see that all three interfaces have joined VLAN 20.
Supplement: Basic usage of switch
As a basic core switch, it is used to connect multiple wired devices: The network structure is shown below, and the basic connection refers to the above method/step 1: Basic connection mode.
Used for network isolation: For some switches with good functions, you can select the network isolation mode through the mode selection switch to realize the function of network isolation. Only ordinary ports and uplink ports are allowed to communicate, and ordinary ports are isolated from each other and cannot communicate.
Besides being used as a core switch (central switch), it can also be used as an expansion switch (access switch) to expand the network.
Put it on the router and expand the network cable of the network provider (for a network with multiple IPS on one line). After the connection, different routers use different IP to connect to the public network.
Related reading: Frequently asked questions about switch hardware failure.
Power failure:
Due to unstable external power supply, aging power cord or lightning strike, the power supply is damaged or the fan stops and cannot work normally.
Due to the power supply, other parts in the machine are often damaged.
If the power indicator on the panel is green, it is normal; If the indicator light goes out, the power supply of the switch is not normal.
This kind of problem is easy to find, solve and prevent.
In view of this kind of fault, external power supply should be done first. Generally, independent power supply is provided by introducing independent power lines and installing voltage regulators to avoid the phenomenon of instantaneous voltage being too high or too low.
If conditions permit, UPS (Uninterruptible Power Supply) can be added to ensure the normal power supply of the switch. Some UPS provide voltage stabilizing function, while others do not. Pay attention to your choice.