IP
IP stands for Internet Protocol.
- How do I locate a device
- How to encapsulate data and communicate with other devices
The ping command is used to check whether the network is normal
- Open the terminal and enter ping baidu.com
URL: Uniform resource locator, commonly known as web address
The full name of the URL is Uniform Resource Locator
What parts the URL contains
Protocol + Domain name or IP address + port + path + query parameters + anchor
Protocol: INCLUDES HTTP and HTTPS
Port: The network port number on the server. The default ports are 80 and 443. There are more than 60,000 ports in total, but ports are generally not displayed
Path: Which part of the site you want to visit
Query parameters: what content do you want to view this url
Anchor point: The location of which part of the content
DNS stands for Domain Name System which is a System that links Domain names to IP addresses
Nslookup is used to query the IP address of a website
The domain name
——— domain name suffixes are generally more than 1000, such as. Com,. Xyz,. Top,. Wang, pub,. Xin, and. Net
TLDS fall into two categories:
- More than 200 countries have been assigned top-level domain names in accordance with ISO3166 country codes, such as CN in China, US in the United States, JP in Japan, etc.
- The second is the international top-level domain name, such as.com for industrial and commercial enterprises,.net for network providers, auspicious, enthusiastic and diligent. Red,.org for non-profit organizations, etc.
Top-level domain
- The level-1 domain name contains only one “. And “.” The left side should have content fields, such as Taobao.com, baidu.com.
The secondary domain name
- Red, reci. Baike. Red, Paimai.taobao.com, baike.baidu.com and so on.
Level 3 domain names
- A three-level domain name consists of letters (A to Z, A to Z, uppercase and lowercase), digits (0 to 9), and hyphens (-). Real dots (.) are used between each level of domain names. Connect. The length of a level 3 domain name cannot exceed 20 characters.