If you're an IT professional, you must have an understanding of how DNS works.
DNS is a fundamental part of how the internet works, and understanding its intricacies is important to stay ahead of the curve in the IT world.
π Think of DNS as the internet's phonebook. π It's the hero that turns friendly domain names (like www.mypage.com) into IP addresses that computers use to chat! π»π¨οΈ
1οΈβ£ You type a URL into your browser. π₯οΈ Your computer first checks its local resources. This includes:
ββπ The host file - a simple text file mapping domain names to IP addresses.
ββπ¦ Various caches - mini storage areas in your computer, operating system, and router where recently visited website addresses are stored.
ββThis quick check lets your computer find the IP address of a website without needing to ask a DNS server. π
ο»Ώ2οΈβ£ If the domain name isn't in the host file or any of the caches, your computer sends a request π to a DNS server.
ο»ΏThe server searches its database and returns the correct IP address to your computer. π―
ο»Ώ3οΈβ£ Once your computer gets the IP address from the DNS server, it uses that address to connect to the website. π It also stores the domain name and IP address in its DNS cache for quick access the next time you visit the website. π
ο»Ώπ³ DNS is a hierarchical system, with DNS servers arranged in a tree-like structure. π²
ο»ΏThis structure, known as the DNS namespace, allows for efficient and quick resolution of domain names to IP addresses, ensuring the smooth functioning of the internet. π
ο»ΏβοΈ Now, let's consider how DNS operates in today's expansive Hybrid Multi-Cloud environments. Public Clouds resolve their Internal FQDNs to Service Endpoints using:
ββπ οΈ The Provider's own DNS Resolvers,
ββπ·οΈ C-Name aliases in Private DNS Zones,
ββπ And Virtual Network Links.
ο»ΏTo resolve these FQDNs from another Cloud (Private or Public), it requires Conditional Forwarding and additional Routing between the EDGEs with NAT/SNAT. π While SNAT/NAT might not always be necessary, it's good to have for ensuring seamless interconnectivity. π
ο»ΏπΌοΈ The attached gif above simplifies the DNS process, but remember, in today's multi-cloud environment, the process is much more complex and fascinating! π©οΈ