4) Routing and protocols (RIP, OSPF, BGP) and DNS

How global routing systems, dynamic protocols, and name resolution via DNS work.

Introduction to Routing

Routing or routing is the process that determines the optimal path that a data packet must take through a series of interconnected networks.

This crucial task is performed by routers, dedicated machines that exchange information about network topologies through routing protocols.

Static and Dynamic Routing

Static routing requires manual configuration of routes by the administrator, ideal for very small and stable networks.

Dynamic routing relies on protocols that can autonomously update routing tables as the network topology changes.

RIP (Routing Information Protocol) Protocol

RIP is a Distance-Vector type protocol that uses hop count to evaluate the best path.

It limits the maximum path to 15 hops, making it suitable only for small-sized corporate networks.

OSPF (Open Shortest Path First) Protocol

OSPF is a Link-State type protocol based on Dijkstra's algorithm, extremely fast in convergence and loop-free.

It divides the network into hierarchical areas to effectively scale and reduce the exchange of update packets between routers.

BGP (Border Gateway Protocol) Protocol

BGP is the cornerstone protocol of the Internet, classified as Path-Vector, used to route traffic between different Autonomous Systems (AS).

It manages the complex global network based on commercial policies, peering agreements, and advanced security parameters.

Domain Name System (DNS)

Alongside physical routing is DNS, the system that translates human-readable domain names into numerical IP addresses.

DNS is a hierarchical and globally distributed structure, starting from Root Nameservers and down to authoritative servers.

Recursive resolution queries servers in sequence to map, for example, "socratico.online" to the correct IP address.

The main DNS records include A records for IPv4, AAAA for IPv6, CNAME for aliases, and MX for email servers.

Conclusions

The synergy between efficient routing and a reactive DNS system constitutes the invisible soul that allows the web to respond instantly to every click.

🔗 Resources and References

Wikipedia - Instradamento Cloudflare - Routing Wikipedia - DNS Cloudflare - Domain Name System