Question

Consider a situation in which a cyberterrorist makes all the DNS servers in the world crash simultaneously. How does this change one's ability to use the Internet?

Short answer

Without DNS, users can't access websites via domain names, impacting normal internet use.

Step-by-step solution

Understanding DNS Role

DNS stands for Domain Name System, and its primary function is to translate human-friendly domain names (like www.example.com) into IP addresses (like 192.168.1.1), which computers use to identify each other on the network. Without DNS, users would need to know the precise IP addresses of the websites they want to visit.

Impact of DNS Failure

When all DNS servers crash, the translation from domain names to IP addresses fails. This means that users will be unable to access websites using domain names, severely limiting access to internet resources. Devices relying on domain names will not be able to connect to the desired services or websites.

Direct IP Access

If a user knows the specific IP address of a website, they can access the site by entering the IP address directly into their browser. However, this is impractical for regular use, as most users do not memorize IP addresses, and many services do not operate solely on fixed IP addresses.

Use of Cached Data

Some devices may have previously resolved IP addresses cached, temporarily allowing access to certain websites. This access is limited and temporary, as caches will not have all necessary IP addresses and may expire.

Relying on Local DNS Servers

If local DNS servers (such as those in individual ISPs) are operational and have cached data, they can still resolve some domain names. However, their cache is limited and not a complete solution nor a long-term fix.

Alternative Methods

Advanced users might use alternative methods like changing their DNS to a private one that is still operational, if possible. Networks may employ workarounds such as establishing direct IP routes where feasible, but the average user won't have easy access to these solutions.

Key concepts

Domain Name System

The Domain Name System (DNS) is like the phonebook of the Internet. It helps us to connect to websites by translating easy-to-remember domain names, such as **www.example.com**, into IP addresses, like **192.168.1.1**. This is crucial because computers communicate using IP addresses instead of domain names. Without DNS, surfing the web would require memorizing the complex number strings of IP addresses.
When DNS servers are operational, they act as a bridge, helping us hop from user-friendly domain names to computer-friendly IP addresses. However, if DNS servers were to fail, this bridge would collapse. Accessing web resources would become nearly impossible unless you knew the technical IP addresses. This function of DNS makes it the backbone of seamless Internet browsing, ensuring users have a smooth and intuitive experience.

IP addresses

IP addresses are unique identifiers for devices on a network, much like postal addresses are for houses. They allow computers to locate and communicate with each other over the Internet. Each device connected to the Internet has an associated IP address, which comes in two main versions: IPv4 and IPv6. While IPv4 is more common, IPv6 was introduced to address the growing number of online devices.
When DNS isn't working, users must rely on these numerical labels to access online resources directly. However, remembering these strings is not practical. Generally, random users won't memorize these complex sequences or know which IP corresponds to which website. While tech-savvy individuals may find the IP-based navigation feasible, for most users, it complicates the otherwise simple task of internet browsing.

Internet access

Internet access is our ability to connect to the vast resources and services available online. The pathway to such access is largely facilitated by the DNS, which allows us to navigate to sites and services using intuitive domain names.
If DNS servers crash, internet access as we know it is severely compromised. Users would struggle to find websites since they wouldn't automatically resolve domain names to IP addresses. Directly inputting IP addresses into browsers becomes the only workaround, but it is inefficient and cumbersome. Despite this challenge, limited access can still be achieved using cached data or through accessible local DNS servers, but these solutions are typically temporary and incomplete.

Cached data

Cached data refers to temporarily stored data that can be accessed quickly when needed without continuously fetching from the original source. In the context of DNS and Internet access, cached data can store previously resolved IP addresses, allowing a user to visit websites despite a DNS server crash.
However, this reliance on cached data is a short-term remedy. Over time, caches can expire, and their limited scope means they don't cover every desired resource. Also, if any changes occur in the IP addresses or domain structures, these caches won't update unless re-verified against live DNS data. Local DNS servers might also retain caches, but like on individual devices, they are not infallible and would gradually empty as resources change or expire. This makes caching a temporary and limited band-aid until DNS systems are restored.