1. What parts does the URL contain and what does each part do

  • agreement
  • The domain name or IP
  • The port number
  • The path
  • Query string
  • The anchor

2. What is the function of DNS? How to use nslookup command

DNS matches domain names with IP addresses

Nslookup Function: Queries DNS records to check whether domain names are resolved properly and diagnose network faults.

Nslookup command:

  1. Query domain name directly:

Nslookup domain[dns-server] nslookup domain[dns-server]

Example: nslookupwww.163.com

  1. Querying Other Records

Nslookup -qt=type domain[dns-server] nslookup -qt=type domain[dns-server]

Example: nslookup -qt=CNAME www.163.com

  1. Query more specific information

Nslookup -d [other parameters]domain[dns-server]

3. What is the function of IP? How does ping work

IP basically agrees on two things:

  1. How do I locate a device
  2. How to encapsulate data packets for communication with other devices

Ping command usage:

  1. Ping the IP address
  2. Ping -t: ping the specified computer continuously until the administrator is interrupted
  3. Ping-a: ping-a resolves the computer name and NetBios name. The host name can be resolved by ping its IP address

4. What is a domain name

A domain name is an alternate name for an IP address. The most common types of domain names are com, CN, net, org and cc