\subsection*{Practice 3.3: Router Configuration and Security (Subtemas 3.5 y 3.6)}

\begin{objetivopractica}
The student will explore fundamental router operation by creating simple network configurations and performing basic router programming tasks, while also implementing basic security features. This practice will demonstrate how routers connect different network segments and provide security services to protect network infrastructure.
\end{objetivopractica}

The practice begins with the student creating a new GNS3 project named "Router Configuration and Security." They will build a multi-segment network topology that requires routing functionality and implement basic security measures.

\definicion{router}{A network device that forwards packets between different network segments based on IP address information}

The student creates a basic routing scenario by placing one router and four PCs in the GNS3 workspace. They connect two PCs to each router interface, creating two separate network segments that require routing for inter-segment communication.

% \includegraphics[width=\textwidth]{figuras/captura33_router_topology.png}

The student accesses the router console and performs basic configuration tasks such as setting interface IP addresses. They configure the first interface with 192.168.1.1/24 and the second interface with 192.168.2.1/24 to create distinct network segments.

\definicion{router interface}{A connection point on a router that connects to a specific network segment and has its own IP address}

The practice includes configuring PC IP addresses to match their respective network segments. PCs on the first segment receive addresses like 192.168.1.10 and 192.168.1.20, while PCs on the second segment use 192.168.2.10 and 192.168.2.20.

The student examines the router's routing table by using basic show commands. They observe how directly connected networks appear automatically in the routing table when interfaces are configured and operational.

\definicion{routing table}{A database that routers maintain to determine where to forward packets based on destination addresses}

% \href{https://www.youtube.com/watch?v=XXXXXXX}{Router configuration and security basics}

The practice includes testing basic routing functionality by performing ping tests between devices on different network segments. The student observes how the router forwards packets between segments while maintaining separate broadcast domains.

The student examines packet forwarding decisions by capturing traffic on router interfaces using Wireshark. They observe how routers examine destination IP addresses and make forwarding decisions based on routing table entries.

\definicion{packet forwarding}{The process by which routers send packets toward their destinations based on routing table information}

% \includegraphics[width=\textwidth]{figuras/captura33_packet_forwarding.png}

The practice includes examining default gateway configuration on PC devices. The student configures PCs to use their respective router interface as the default gateway, enabling communication beyond the local network segment.

\definicion{default gateway}{The router interface that devices use to reach destinations outside their local network segment}

The student transitions to security configuration by implementing basic password protection on the router. They set console passwords, enable passwords, and configure user accounts to control access to router management functions.

\definicion{console password}{A password that controls access to network device command-line interfaces}

The practice includes configuring remote access security by setting up SSH access to the router and disabling less secure protocols such as Telnet. The student understands how encrypted remote access protects administrative communications.

\definicion{SSH}{Secure Shell - an encrypted protocol for secure remote access to network devices}

% \includegraphics[width=\textwidth]{figuras/captura33_security_config.png}

The student implements basic access control using simple access control lists that filter traffic based on source and destination addresses. They create basic rules that permit or deny specific types of network communication.

\definicion{access control list}{A set of rules that routers use to permit or deny network traffic based on specified criteria}

The practice includes examining router interface status and statistics using basic monitoring commands. The student observes interface up/down status, packet counts, and error statistics that help evaluate router performance and security.

The student explores basic router monitoring for security purposes by examining device logs and traffic statistics that help identify unusual network activity. They understand how monitoring provides visibility into potential security threats.

The practice includes documenting the router configuration process by recording the commands used to set up interfaces, security features, and basic functionality. The student creates a configuration backup that preserves their router settings.

The practice concludes with the student creating a comprehensive router configuration that incorporates both routing functionality and basic security measures. They understand how routers provide both connectivity and protection services for network infrastructure.

\begin{rubrica}
The student must submit a report containing clear evidence of completing the practice. The document should include screenshots, explanations of observations, and reflection on the learning achieved. The submission must demonstrate that the student understood the concept and was able to apply it with the indicated software.
\end{rubrica}

\subsection*{Suggested Report Format}

\textbf{Title:} Practice 3.3 - Router Configuration and Security \\
\textbf{Objective:} Written by the student according to what they understood. \\
\textbf{Development:} Clear narration of actions performed. \\
\textbf{Evidence:} Screenshots or other data obtained. \\
\textbf{Conclusions:} Technical reflection on what was learned. \\
\textbf{Personal Opinion:} Student's free opinion about the usefulness or difficulty of the practice.