CCNA2 Study Notes

CCNA2 – Switching, Routing and Wireless Essentials v7.0 (SRWE) Study Notes

Command History Feature

  • Tasks Accomplished with Command History:
    • View a list of commands entered in a previous session.
    • Recall up to 15 command lines by default.
    • Other options include:
    • Set the command history buffer size.
    • Recall previously entered commands.
    • Save command lines in a log file for future reference.

Boot Sequence of a Switch

  • First Action When a Switch is Powered On:
    • Load the boot loader software.

Password Reset on Router

  • Requirements for Resetting a Lost Password on a Router:
    • Physical access to the router.

SSH Configuration on Switch

  • Required Command for SSH Access:
    • Must enter the command username username secret secret along with login local.

Auto-MDIX Setting Command

  • Command that Displays Auto-MDIX Setting:
    • show interfaces

Ethernet Connection Duplex Configuration

  • Full Duplex vs Half Duplex:
    • Late collisions observed only on the half-duplex end of the connection.

Setting BOOT Environment Variable

  • Command to Set BOOT Environment Variable for IOS Image on Switch:
    • boot system

Locating IOS Image

  • Used by Switch to Load IOS Image:
    • BOOT environment variable.

Security Protocol for Remote Connections

  • Protocol that Adds Security to Remote Connections:
    • SSH

IPv4 Loopback Interface

  • Characteristics of IPv4 Loopback on Cisco IOS Router:
    • It is a logical interface internal to the router.
    • No shutdown command is not required to place this interface in an UP state.

Minimum Ethernet Frame Size

  • Minimum Frame Size to Avoid Runt Frame Discarding:
    • 64 bytes

Switch Bootup Sequence

  • Boot Loader Execution Timing:
    • Executed after CPU initialization.

Impact of Adding Layer 2 Switch on Network

  • Effects of Layer 2 Switch on a Network:
    • Increase in the size of the collision domain.

Cut-Through Switching Characteristics

  • Description of Cut-Through Switching:
    • Error-free fragments are forwarded without error checking, thus reducing latency.

Hub vs Layer 2 LAN Switch

  • Significant Difference between Hub and Switch:
    • A hub extends a collision domain while a switch divides collision domains.

Ethernet Switch Frame Forwarding Decisions

  • Basis of Frame Forwarding Decisions:
    • Based on MAC address and port mappings in the CAM table.

Switch Buffers and Network Performance

  • Effect of Switch Buffers on Network Performance:
    • They temporarily store frames received, preventing premature frame discarding during congestion.

Characteristics of Switches

  • Switch Characteristics Helping Alleviate Network Congestion:

    • Fast internal switching.

  • Switch Component Reducing Packet Handling Time:

    • ASIC (Application Specific Integrated Circuit).

Information Added to Switch Table

  • Information from Incoming Frames:
    • Source MAC address and incoming port number.

Switching Methods and Error Checking

  • Switching Method Ensuring Error-Free Frame Forwarding:
    • Store-and-forward.

Broadcast Domains in a Network

  • Number of Displayed Broadcast Domains:
    • Depends on the network configuration exhibited.

Disabling DTP in Network Management

  • When to Disable DTP:
    • When connecting to a non-Cisco switch.
    • When links should not be trunking.

Characteristics of Native VLAN

  • Characteristics of the Native VLAN:
    • Carries user-generated traffic, typically untagged across trunk links.
    • Provides a common identifier for both ends of a trunk.

VLAN Removal Command

  • Command to Remove VLAN 100 from Switch:
    • no vlan 100

VLAN Broadcast Frame Behavior

  • Behavior When Device in VLAN 20 Sends Broadcast:
    • Only devices in VLAN 20 see the frame.

Enabling Communication Between VLANs

  • Requirement for Communication in Router-On-a-Stick Approach:
    • A switch with a trunk port connecting to the router is needed.

VLAN Assignment Removal Consequences

  • Effect of Deleting VLAN Assignment on Switch Ports:
    • Ports return to VLAN1, the default VLAN.

Voice VLAN Configuration Steps

  • Steps to Configure Voice VLAN on a Switch Port:
    • Assign the voice VLAN to the port.
    • Enable spanning-tree PortFast on the interface.
    • Ensure voice traffic is trust-tagged with a CoS.
    • Add voice VLAN.

Show Interfaces Trunk Command Analysis

  • Conclusion from show interfaces trunk Command Output:
    • Determines if an interface has been correctly configured as a trunk.

Inter-VLAN Routing Configuration Errors

  • Common Errors in Inter-VLAN Routing Configuration:
    • Missing no shutdown commands on subinterfaces.
    • Incorrect subinterface configurations with encapsulation details.

Routed Ports in Layer 3 Switches

  • Characteristic of Routed Ports:
    • They are not assigned to any VLANs and are commonly used as WAN links.

VLAN Configuration on Router

  • Required Effect of a Correct Configuration on a Router:
    • Ensures appropriate communication across VLANs.

Configuration Commands on Cisco 2960 Switch

  • Understanding Various Configuration Commands:
    • ip address 172.18.33.88 255.255.255.0 applies IPv4 address.
    • configure terminal enters global configuration mode.
    • shutdown disables a port.
    • duplex full sets full-duplex mode.

Types of VLANs

  • Different Types of VLANs Defined:

    • Data VLAN: Carries user-generated traffic.
    • Voice VLAN: Dedicated to IP Phones, ensuring quality bandwidth.
    • Management VLAN: Reserved for network management traffic.
    • Native VLAN: Supports untagged traffic.

  • DHCP Message Types:

    • DHCPDISCOVER: Client initiating a message to find a DHCP server.
    • DHCPOFFER: Server response to initial request.
    • DHCPREQUEST: Client accepting IP address.
    • DHCPACK: Confirmation of IP lease acceptance.

Conclusion

  • This document summarizes key concepts from the CCNA2 SRWE coursework and should serve as a comprehensive study guide for exam preparation, emphasizing detailed terms, commands, and network configurations pertinent to switching, routing, and wireless essentials in the CCNA curriculum.