CCNA | P1: Fundamentals Of Computer Networks | C3: Fundamentals Of WANs and IP Routing
Greetings, and get ready for an exciting journey as we dive into the fascinating world of Wide Area Networks (WANs) and IP routing in this blog post! 🚀
What Are WANs
WANs are the superheroes of the networking world, spanning across cities, countries, or even continents! They act as the bridges, connecting different Local Area Networks (LANs) or other types of networks, such as the vast expanse of the Internet. 🌐
Now, let’s talk about the magic behind the scenes - IP routing.
It’s like the GPS of the digital world, finding the best path for a packet of data to travel from its source to its destination across a WAN. It’s a complex dance of protocols, algorithms, and devices working in harmony to ensure efficient and reliable data transmission. 📡
Below is an example of a simple diagram illustrating a basic network architecture, including LAN (Local Area Network) and WAN (Wide Area Network) connections.
Here’s a brief description based on the image:
The image has a yellow background divided into three sections labeled “LAN”, “WAN”, and “LAN”.
On the left side, there is a computer labeled “PC 1” connected to a switch labeled “Sw 1”, representing the first LAN.
In the middle section labeled as “WAN”, there are two routers labeled “R1” and “R2” connected by an arrow, indicating data flow or connection between them.
On the right side, another computer labeled “PC 2” is connected to another switch labeled “Sw 2”, representing the second LAN.
Both switches “Sw 1” and “Sw 2” are connected to their respective routers “R1” and “R2”.
This setup allows for connectivity between the two LANs through the WAN.
The main components of a WAN are:
1. Routers are like the traffic cops of the digital world, connecting different networks and directing packets based on their destination IP addresses.
2. Switches are the social butterflies, connecting multiple devices within a network and forwarding packets based on their MAC addresses.
3. Links are the highways, the physical or logical connections between routers and switches. These could be cables, wireless signals, or virtual circuits. Each link has its own unique characteristics, such as bandwidth, latency, reliability, and cost. 🚦
challenges of WANs
One of the biggest challenges of WANs is managing the complexity and diversity of the network topology. It’s like navigating through a maze with many possible paths for a packet to travel from one network to another.
Not all paths are created equal. Some may be faster, more reliable, or cheaper than others. Some paths may be congested, broken, or unavailable at certain times.
So, how does a router decide which path to use for each packet? That’s where the magic of IP routing comes in! 🧭
IP routing is built upon two pillars: Routing tables and routing protocols.
1.Routing Tables
Think of it as a treasure map, storing valuable information about the network topology, such as the IP addresses of neighboring routers, the cost of each link, and the best path to reach each destination network.
2. Routing protocol
It is like the compass guiding the ship, a set of rules and messages that routers use to exchange information about the network topology and update their routing tables. There are several types of routing protocols, each with its own unique characteristics, including static routing, dynamic routing, distance vector routing, link state routing, and hybrid routing.
Types of routing protocols
1. Static routing is the old-school, no-frills approach to IP routing. It involves manually configuring each router with a static routing table that specifies the next hop for each destination network. While static routing is straightforward to implement and secure, it’s not without its drawbacks. It’s like a rigid old tree that doesn’t sway with the wind; it doesn’t adapt to changes in the network topology, such as link failures or congestion. It requires a significant amount of manual work and maintenance and doesn’t scale well for large or complex networks.
2. Dynamic routing, on the other hand, is the flexible, adaptable cousin of static routing. It involves using a dynamic routing protocol that automatically updates the routing tables based on the current state of the network topology. While dynamic routing is more flexible and adaptive than static routing, it also comes with its own set of challenges. It’s like a high-performance sports car that requires more processing power and memory for each router. If not configured properly, it may introduce instability or inconsistency in the network. It may also be vulnerable to attacks or misconfigurations by malicious or faulty routers.
3. Distance vector routing is a type of dynamic routing protocol that uses the distance (or hop count) and direction (or vector) to each destination network as the main criteria for choosing the best path. It’s like a relay race where each router maintains a distance vector table that contains the distance and next hop for each destination network. Each router periodically broadcasts its distance vector table to its neighbors, passing the baton. Each router then updates its own table based on the information received from its neighbors. This process is repeated until all routers have consistent and accurate information about the network topology.
4. Link state routing is another type of dynamic routing protocol that uses the state (or status) and cost (or weight) of each link as the main criteria for choosing the best path. It’s like a real-time traffic report where each router maintains a link state database that contains information about all links in the network, such as their bandwidth, latency, reliability, and cost. Each router periodically floods its link state database to all other routers in the network, broadcasting the latest traffic updates. Each router then uses a shortest path algorithm, such as Dijkstra’s algorithm, to calculate the best path to each destination network based on the information in its link state database.
5. Hybrid routing is the best of both worlds, a combination of distance vector and link state routing protocols that tries to balance the advantages and disadvantages of both approaches. It’s like a bilingual person who uses distance vector techniques for local communication within a subnetwork or area, and link state techniques for global communication between different subnetworks or areas. An example of a hybrid routing protocol is the Enhanced Interior Gateway Routing Protocol (EIGRP).
In conclusion, WANs and IP routing are the unsung heroes of computer networking, enabling data transmission across vast geographical areas. WANs are like the highways of the digital world, consisting of routers, switches, and links that connect different networks together. IP routing is the GPS of this digital highway, consisting of routing tables and routing protocols that help routers find the best path for each packet across a WAN. 🚀
