What happened when you search in your browser?
Juan David Tuta Botero
Data Science | Machine Learning | Artificial Intelligence
The Internet has become one of the most important tools in the current society. It is hard to believe any activity that isn’t closely related to it, for example, exercise, nutrition, driving, and almost impossible to imagine our work without it. But it has become so ingrained in our lives that we just assume that it exists and functions by itself, and for us professionals and tech scientists at least, we should have a notion of how the internet works. In this article, we will follow the process of what happens when you type a direction in your browser and what are the steps that end being showing an HTML page in your screen which one you can interact with.
DNS
All computers with the Internet, from your smartphone or laptop to the servers with the content of mass retail websites, find and communicate with each other through the use of numbers. These numbers are known as IP addresses. When you open a web browser and visit a site, you don't need to remember and enter a long number. Instead, you can enter a domain name like example.com and still end up in the right place.
A DNS service such as Amazon Route 53 is a globally distributed service that converts human-readable names, such as www.example.com, into the numeric IP addresses, such as 192.0.2.1, that computers use to connect. The Internet's DNS system works like a phone book where the mapping between names and numbers is managed. DNS servers convert name requests to IP addresses and control which server an end-user will be directed to when entering a domain name in their web browser. These requests are called inquiries.?
HTTPS port 443
Now that we found the direction of the page we must connect to the server, we are doing that using a port. A port is a virtual numbered address that’s used as a communication endpoint by transport layer protocols like UDP (user diagram protocol) or TCP (transmission control protocol). Network ports direct traffic to the right places, they help the devices involved identify which service is being requested.?
For instance, the port that’s responsible for handling all unencrypted HTTP web traffic is port 80. When we use a TLS certificate, the communication channel between the browser and the server gets encrypted to protect all sensitive data exchanges.
All such secure transfers are done using port 443, the standard port for HTTPS traffic. However, HTTPS port 443 also supports sites to be available over HTTP connections. If the site uses HTTPS but is unavailable over port 443 for any reason, port 80 will step in to load the HTTPS-enabled website.
HTTPS/SSL
SSL is the acronym for Secure Sockets Layer, the standard technology for keeping an Internet connection secure, as well as for protecting any confidential information that is sent between two systems and preventing criminals from reading and modifying any data that is transferred, including information that could be considered personal. The two systems can be a server and a client (for example, a shopping website and a browser) or from server to server (for example, an application with personally identifiable information or payroll data).?
Load Balancer
Now we are connected and send out the request for the information to pass through a load balancer. A load balancer acts as the “traffic cop” sitting in front of your servers and routing client requests across all servers capable of fulfilling those requests in a manner that maximizes speed and capacity utilization and ensures that no one server is overworked, which could degrade performance. If a single server goes down, the load balancer redirects traffic to the remaining online servers. When a new server is added to the server group, the load balancer automatically starts to send requests to it.
In this manner, a load balancer performs the following functions:
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Firewall
Now we have the encrypted information and distributed it effectively we need to protect our system from malicious requests and for that, we use a firewall, which is a network security device that monitors incoming and outgoing network traffic and permits or blocks data packets based on a set of security rules. Its purpose is to establish a barrier between your internal network and incoming traffic from external sources (such as the internet) in order to block malicious traffic like viruses and hackers.
Firewalls carefully analyze incoming traffic based on pre-established rules and filter traffic coming from unsecured or suspicious sources to prevent attacks. Firewalls guard traffic at a computer’s entry point called ports, which is where information is exchanged with external devices. For example, “Source address 172.18.1.1 is allowed to reach destination 172.18.2.1 over port 22."
Think of IP addresses as houses, and port numbers as rooms within the house. Only trusted people (source addresses) are allowed to enter the house (destination address) at all—then it’s further filtered so that people within the house are only allowed to access certain rooms (destination ports), depending on if they're the owner, a child, or a guest. The owner is allowed into any room (any port), while children and guests are allowed into a certain set of rooms (specific ports).
Application Servers
Application servers physically or virtually sit between database servers storing application data and web servers communicating with clients. App servers and akin middleware are the operating systems supporting an application’s development and delivery. Whether it’s a desktop, mobile, or web app, application servers play a critical role in connecting a world of devices.
We look at how application servers fit into a network’s service architecture, how app servers support web servers, native applications, and mobile apps, and the current state of application servers in the 2020s.
Billions of web clients make HTTP requests every day, expecting instant access to you-name-the-app. Headspace during the morning routine, Google Docs for the extensive report, Twitter during a coffee break, no matter the application in use, it’s being pulled from an application server and delivered via a web server.
Web servers are responsible for serving web clients' HTTP requests with HTTP responses. Unlike app servers, the webserver design is light enough to process static data requests for multiple applications (or websites) while maintaining security. Dynamic requests, often in the form of applications, require additional assistance.
?Bibliography
https://www.forcepoint.com/es/cyber-edu/firewall
https://www.serverwatch.com/guides/application-server/