Switch settings for linux notes

Switch storage media include NvRam, Ram, and Flash. Switch operation

Switch storage media include NvRam, Ram, and Flash. The Switch operating system and Vlan information are stored in flash, startup-config is stored in NvRam, and NvRam provides its own power supply system.

I. working principle of the vSwitch:

1: accept the frame from the port

2: record the mac address, vlan number, and port number of the corresponding port in the table,

3: If the table does not exist, broadcast based on the corresponding vlan number.

2. a Switch is a device that works on the data link layer. There are two ways to set a Switch: The first is to set a Switch through the console port of the Switch connected to the computer through the full anti-line. You can also set it remotely. The Switch can only be configured on the computer for the first time.

There are four Switch modes: Normal user mode, enable mode, configure terminal mode, and interface mode.

In normal user mode, you can only query the basic information of a Switch. In enable mode, you can configure a password at this level.

Configure terminal is the global configuration mode. It configures the Switch as a whole. Interface is the interface mode, which is used to configure specific interfaces.

3. configure common commands:

1: configure the console port password: enter enable mode. then enable line console 0 password, enable line console 0 secret password. Enter login to make the password take effect. The password is in plain text.

2 :? View help and complete commands.

3: press ctrl + z to exit the upper-layer mode, and press ctrl + shift + 6 to end the command.

4: show to view various information. For example, show ip interface brief

5: show runnig-config: view the current Switch configuration

6: show startup-config

7: erase nvram deletes saved information

8: reload the system.

9: add a vlan to the vlan Id. name the vlan name.

10: enter the port configuration mode, switchport access vlan vlan_id

11: delete vlan no switchport access vlan ID from the port

12: interface range f0/1-5 configure multiple ports at a time

13: switchport trunk allowed vlan remove vlan_id delete a vlan from this trunk port.

4. there are four Switch port modes:

Access, Trunk, Dynamic desirable, and Dynamic auto modes.

Access is the Access mode. All initialized ports are in access mode.

The Trunk is in the Trunk mode. when the two switches are connected and the ports are in the Trunk mode, the Trunk link is used. all VLANs can pass through.

Dynamic desirable is a Dynamic desire mode. when one of the two switches is Dynamic desirable, the other can automatically become a dry link in any mode except access.

In Dynamic auto mode, only the Dynamic desirable and Trunk ports can be used as Trunk links.

The so-called Trunk (Trunk link) is the link that all VLANs can pass through. When implementing the mechanism, when the Switch receives a Frame from the port, it must use a trunk link. Swtich will add a four-byte flag to the Frame and remove the flag forwarding when it reaches another Switch.