Principle of switch

1. Switch Principle:

MAC address (globally unique): 48 bits binary composition, 8 bits per segment, a total of 6 segments, after the binary conversion to 16, the first 24 bits are IEEE issued to the manufacturer's unique number, the last 24 bits are the manufacturer's custom number (network card)

(1) Initialize

(2) Learn source MAC address and corresponding interface

(3) Broadcast unknown frames

(4) Response from receiver

(5) Implementation of Unicast Communication

MAC address table empty: ①300s if no communication occurs ② switch shutdown

Second, Cisco switch basic operation:

1. mode basic operation

Switch> //Default is in user mode (current mode is less operable)

Switch# //is currently in privileged mode, which can be entered by typing "en" in user mode (current mode is generally used for viewing)

Switch(config)# //Currently in global configuration mode, which can be entered by typing "conf t" in privileged mode (current mode is generally used to change operations)

Switch(config-if)# //Currently in interface mode, enter "int xx/x" in global configuration mode (current mode is generally used to change interface configuration)

Ctrl+z(return to privileged mode from current mode), exit(return to higher mode from current mode)

2. Common commands (Tab can be completed)

(1) Switch(config)# hostname hostname//Change the current switch hostname

(2) Switch# show version //View current switch version information

(3) Switch# show mac-address-table [dynamic] //View MAC address cache table of current switch

(4) Move the cursor to the beginning of the command line

(5) Move cursor to end of command line

Third, the switch working mode

Note: By default all network devices are in auto mode

Set the duplex mode of the current interface:

Switch(config-if)# duplex {auto | full | half}

Configure the rate of the current interface

Switch(config-if)# speed { 10 | 100 | 1000 | 10000 | auto }