M1

Module 1: Basic Device Configuration

Overview

  • Focuses on Switching, Routing, and Wireless Essentials (SRWE) v7.0.

Module Objectives

  • Objective: Configure devices using security best practices.

    • 1.1 Configure a Switch with Initial Settings

    • 1.2 Configure Switch Ports

    • 1.3 Secure Remote Access

    • 1.4 Basic Router Configuration

    • 1.5 Verify Directly Connected Networks

1.1 Configure a Switch with Initial Settings

Switch Boot Sequence

  • Five-step boot sequence after powering on a switch:

    1. Loads POST (Power-On Self-Test) from ROM to check the CPU subsystem (CPU, RAM, and flash).

    2. Loads the boot loader software from ROM post-POST completion.

    3. Initializes CPU registers and memory mapping/quantity.

    4. Initializes the flash file system on the system board.

    5. Locates and loads the default IOS operating system.

The Boot System Command

  • Switch resumes automatically using the BOOT environment variable.

  • If variable is not set, first executable file is loaded.

  • IOS will initialize interfaces using the startup-config file located in flash.

  • Command:

    • show boot to check current IOS boot file.

    • Example IOS file: c2960-lanbasek9-mz.150-2.SE.bin

Switch Management Access

  • Configure IP address and subnet mask for remote management.

  • Use Switch Virtual Interface (SVI) (not a physical port).

  • Default gateway configuration allows communication with non-directly connected networks.

Setting Up Default Gateway

  • Required for communication with networks beyond the switch.

  • Example configuration:

    • ip address 192.168.10.5 255.255.255.0

    • ip default-gateway 192.168.10.1

SVI Configuration Best Practices

  • Change default management VLAN (VLAN1) to a different VLAN for security reasons.

  • Use appropriate commands to configure the SVI, e.g.:

    • interface vlan 99

    • ip address 172.17.99.11 255.255.255.0

    • no shutdown

1.2 Configure Switch Ports

Duplex Communication

  • Full-duplex: Both ends can send/receive simultaneously, no collisions.

  • Half-duplex: Unidirectional data flow; results in collisions, performance issues.

  • Gigabit Ethernet: Requires full-duplex mode for operation.

Physical Layer Configurations

  • Switch ports can be manually set for duplex and speed settings (default is auto).

  • Auto-negotiation useful in dynamic environments, manual configuration for known devices.

  • Important to match settings to avoid connectivity issues.

Commands for Duplex and Speed Settings

  • Configure interface:

    • Enter interface FastEthernet 0/1

    • Set duplex full

    • Set speed 100

Auto-MDIX

  • Automatically detects cable type required for connection (straight-through or crossover).

  • Enable by mdix auto command; requires speed and duplex set to auto.

1.3 Secure Remote Access

Telnet vs. SSH

  • Telnet: Uses TCP port 23, insecure, plaintext transmission.

  • SSH: Uses TCP port 22, secure, data encrypted during transmission.

Enabling SSH

  • Ensure IOS supports encryption features with show version command.

  • Use show ip ssh to confirm SSH version and configurations.

SSH Operational Verification

  • Use SSH client (e.g., PuTTY) to connect from PC to switch SVI IP address.

  • Proper user authentication required (username, password).

1.4 Basic Router Configuration

Initial Configuration Steps

  • Similar command structures between routers and switches.

  • Basic tasks include naming the device, setting passwords, etc.

Interface Configuration

  • Interfaces require IP configuration and activation (use no shutdown).

  • Useful for testing internal routing processes; configurable loopback interfaces.

1.5 Verify Directly Connected Networks

Verification Commands

  • Use show ip interface brief to check summary and status of interfaces.

  • Use show running-config interface for interface command displays.

  • Routing table displayed using show ip route. Relevant codes: ‘C’ for connected.

Status Verification

  • Ensures interfaces are operational (both status and protocol should be "up").

  • Link-local addresses automatically assigned for IPv6 interfaces.

Module Summary

  • Configured settings and secured access essential for efficient network operation.