How DNS translates domain names to IP addresses and related security issues.
The Domain Name System (DNS) is often called the 'phonebook of the Internet.' Humans access information online through domain names like nytimes.com or espn.com. Web browsers, however, interact through Internet Protocol (IP) addresses. DNS translates domain names to IP addresses so browsers can load Internet resources. The process of a DNS lookup involves a user's computer (the DNS client) querying a series of DNS servers to find the correct IP address for a domain. This usually starts with a local recursive resolver (often provided by your ISP), which then queries the root DNS servers, then the Top-Level Domain (TLD) servers (for .com, .org, etc.), and finally the authoritative nameserver for the specific domain, which holds the actual IP address record. Because DNS is a foundational part of how the internet functions, it's a prime target for attackers. One common attack is DNS Spoofing or Cache Poisoning, where an attacker introduces false DNS data into a resolver's cache. This causes the resolver to return an incorrect IP address, diverting traffic to a malicious site. For example, a user trying to visit their banking website could be redirected to a fake phishing site that looks identical. Another attack is a DNS Amplification Attack, a type of DDoS attack where an attacker sends small DNS queries with a spoofed source IP address (the victim's IP) to many open DNS servers. The servers then send large DNS responses to the victim, overwhelming their system with traffic. Securing DNS often involves using technologies like DNSSEC (DNS Security Extensions), which uses digital signatures to ensure DNS responses are authentic and have not been tampered with.