Introduction to Routing
Routing, or path determination, is the process that determines the optimal path a data packet must take through a series of interconnected networks.
This crucial task is performed by routers, dedicated machines that exchange network topology information 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)
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 enterprise 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 update packet exchange between routers.
BGP (Border Gateway Protocol)
BGP is the cornerstone protocol of the Internet, categorized 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)
Beside physical routing, DNS is 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 descending to authoritative servers.
Recursive resolution queries servers in sequence to map, for example, "socratico.online" to the correct IP address.
Primary DNS records include A records for IPv4, AAAA for IPv6, CNAME for aliases, and MX for mail servers.
Conclusion
The synergy between efficient routing and a responsive DNS system constitutes the invisible backbone that enables the web to respond instantly to every click.