The second day of study at HCNA

The second day of study at HCNA

About subnet

Subnetting:

Given a larger network range, the host can borrow to the network position to divide the original large network range into several small network ranges

Divided network range: determined by the number of digits borrowed

example:

172.16.0.0/23-Large range, borrow 3 bits, write out all the divided network ranges and the IP addresses available in each range
10101100 00010000 00000000 00000000 Original IP address
0.1—0.62
10101100 00010000 00000000 01000000---- 172.16.0.64/26
0.65-0.126
10101100 00010000 00000000 10111110----172.16.0.128/26
0.129-0.190
10101100 00010000 00000000 11000000----172.16.0.192/26
0.193-0.254
10101100 00010000 00000001 00000000----172.16. 1.0/26
1.1-1.62
10101100 00010000 00000001 01000000----172.16.1.64/26
1.65-1.126
10101100 00010000 00000001 10000000----172.16.1.128/26 1.129-1.190
10101100 00010000 00000001 11000000----172.16.1.192/ 26
1.193-1.254 The
last six digits cannot be all 1, otherwise it is the broadcast address

Subnet summary (to divide for a long time must be combined for a long time): take the same bit, go to a different bit

Summary conditions:

1) The mother network is the same (the first three digits are the same)
2) The mask is the same
Example:
172.16.1 (00000001).0/24
172.16.3 (00000011).0/24
172.16.11 (00001011).0/24
172.16 .65. (01000001) 0/24
172.16.111 (01101111) . 0/24

About the network cable

model:

T-568A (RJ-45): green white green orange white blue white orange brown white brown
T-568B (for RJ-11 landline): orange white orange green white blue white green brown white brown

Production tools:

Network cable, wire pliers, crystal head, wire tester

Types of:

Crossover cable: A----B B----A the same layer (in OSI) equipment interconnection
Straight line: A----A B----B different layer (in OSI) equipment interconnection

Huawei device commands

<Huawei>
<>–Representative mode, user mode–simple view and test
Huawei–device name

system-view
[Huawei]-system mode, you can configure
[Huawei]quit / quit

save / save configuration
reboot / restart the device

[Huawei]sysname haha ​​/Modify device name
[haha]

[haha]user-interface console 0 /Enter the console
[haha-ui-console0]set authentication password cipher 123 /set password

[haha]display current-configuration /View the currently effective configuration
[haha]display clock //View the device time

<haha >clock datetime 20:20:20 2019-11-1 /Modify device time

Device command help system:
1) Tab key automatically completes commands
2)? View unknown commands and words
Example: <haha >clock?
Datetime Specify the time and date
daylight-saving-time Configure daylight saving time
timezone Configure time zone
command format Command explanation
3) ↑ ↓ arrow quickly appears one of the entered commands
4 ) "^" appears below a word in the text area is the wrong position