1.Configure IP address for its own as ne device,If the device is new , it need to get its own ip , it need to set either static ip or dhcp ip
2.The browser checks the cache for a DNS record to find the corresponding IP address of maps.google.com.
Browser cache –The browser caches DNS records for some time. Interestingly, the OS does not tell the browser the time-to-live for each DNS record, and so the browser caches them for a fixed duration (varies between browsers, 2 – 30 minutes).
OS cache– If the browser cache does not contain the desired record, the browser makes a system call (gethostbyname in Windows). The OS has its own cache.
Router cache– The request continues on to your router, which typically has its own DNS cache.
ISP DNS cache– The next place checked is the cache ISP’s DNS server. With a cache, naturally.
Recursive search– Your ISP’s DNS server begins a recursive search, from the root nameserver, through the .com top-level nameserver, to Facebook’s nameserver. Normally, the DNS server will have names of the .com nameservers in cache, and so a hit to the root nameserver will not be necessary.
3. If the requested URL is not in the cache, ISP’s DNS server initiates a DNS query to find the IP address of the server that hosts maps.google.com.
The purpose of a DNS query is to search multiple DNS servers on the internet until it finds the correct IP address for the website. This type of search is called a recursive search since the search will continue repeatedly from DNS server to DNS server until it either finds the IP address we need or returns an error response saying it was unable to find it.
In this situation, we would call the ISP’s DNS server a DNS recursor whose responsibility is to find the proper IP address of the intended domain name by asking other DNS servers on the internet for an answer. The other DNS servers are called name servers since they perform a DNS search based on the domain architecture of the website domain name.
Many website URLs we encounter today contain a third-level domain, a second-level domain, and a top-level domain. Each of these levels contains their own name server which is queried during the DNS lookup process.
For maps.google.com, first, the DNS recursor will contact the root name server. The root name server will redirect it to .comdomain name server. .com,name server will redirect it to google.com ,name server.google.com,name server will find the matching IP address for maps.google.com in its’ DNS records and return it to your DNS recursor which will send it back to your browser.
These requests are sent using small data packets which contain information such as the content of the request and the IP address it is destined for (IP address of the DNS recursor). These packets travel through multiple networking equipment between the client and the server before it reaches the correct DNS server. This equipment use routing tables to figure out which way is the fastest possible way for the packet to reach its’ destination. If these packets get lost you’ll get a request failed error. Otherwise, they will reach the correct DNS server, grab the correct IP address, and come back to your browser.
3. Browser initiates a TCP connection with the server.
Once we have an IP address of destination server, browser opens a TCP connection to server, and send http (port 80)/ https (port 443) request through TCP connection.This connection is established using a process called the TCP/IP three-way handshake. This is a three step process where the client and the server exchange SYN(synchronize) and ACK(acknowledge) messages to establish a connection.
Client machine sends a SYN packet to the server over the internet asking if it is open for new connections.
If the server has open ports that can accept and initiate new connections, it’ll respond with an ACKnowledgment of the SYN packet using a SYN/ACK packet.
The client will receive the SYN/ACK packet from the server and will acknowledge it by sending an ACK packet.Then a TCP connection is established for data transmission!
5. The browser sends an HTTP request to the web server.
Request reaches to Network layer for filling TCP header , Transport layer for filling IP header, data link layer for ethernet frame header.Packet flows in the network in digital or cellular.
When information is sent over TCP, we think of it as a sequence of characters (and since everything is bits, then it is just a sequence of bits). The amount of information we can send over the TCP "wire" could be as large as we want -- e.g., a multi-hour movie consisting of Gigabytes of information. To send this stream of bits, TCP uses the IP protocol. It does so by splitting the information into a sequence of IP packets, each of which is individually addressed using the IP address and the port number of the sender and of the receiver, and each of which is individually routed through the Internet by being stored and forwarded from router to router along a path from the sender to the receiver