Module 1 Flashcards
(45 cards)
What are the five steps in the switch boot sequence?
Load POST (Power-On Self-Test) from ROM.
Load boot loader software from ROM.
Boot loader initializes CPU registers.
Boot loader initializes the flash file system.
Boot loader loads IOS and hands control to it.
How is the BOOT environment variable set?
Use the boot system command in global configuration mode. Example:
boot system flash:<path-to-IOS-file>.</path-to-IOS-file>
What do the following switch LEDs indicate?
SYST
RPS
STAT
DUPLX
SPEED
PoE
SYST: System power and functionality.
RPS: Redundant Power Supply status.
STAT: Port status (default mode).
DUPLX: Port duplex mode.
SPEED: Port speed mode.
PoE: Power over Ethernet status.
How do you access the boot loader to recover from a system crash?
Connect via console cable.
Power cycle the switch.
Press and hold the Mode button until the SYST LED turns amber, then green.
Use boot loader commands to recover (e.g., dir to view files).
What is required to manage a switch remotely?
An IP address and subnet mask on the switch.
A default gateway if managing from a different network.
How do you configure an SVI for management?
Enter global config mode: configure terminal.
Enter interface config mode: interface vlan <vlan-id>.
Assign IP address: ip address <ip> <subnet-mask>.
Enable the interface: no shutdown.
Save config: copy running-config startup-config.</subnet-mask></ip></vlan-id>
What is the difference between full-duplex and half-duplex communication?
Full-duplex: Simultaneous two-way communication (no collisions).
Half-duplex: One-way communication at a time (collisions possible).
What is Auto-MDIX, and why is it useful?
Auto-MDIX automatically detects and configures cable type (straight-through or crossover).
It eliminates the need for specific cable types when connecting devices.
Why is SSH preferred over Telnet?
Telnet: Unencrypted, insecure (uses plaintext).
SSH: Encrypted, secure (uses TCP port 22).
What are the steps to configure SSH on a switch?
Verify SSH support: show ip ssh.
Configure IP domain: ip domain-name <domain>.
Generate RSA keys: crypto key generate rsa.
Configure user authentication: username <name> secret <password>.
Enable SSH on VTY lines: transport input ssh.
Enable SSH version 2: ip ssh version 2.</password></name></domain>
What are the initial steps to configure a router?
Name the device: hostname <name>.
Set passwords (enable secret, console, VTY).
Configure a banner: banner motd <message>.
Save configuration: copy running-config startup-config.</message></name>
What is required to activate a router interface?
Assign an IP address: ip address <ip> <subnet-mask>.
Enable the interface: no shutdown.
(Optional) Add a description: description <text>.</text></subnet-mask></ip>
What is a loopback interface, and why is it useful?
A logical interface internal to the router.
Always ‘up’ as long as the router is functioning.
Useful for testing, management, and simulating networks.
What commands verify interface status and configuration?
show ip interface brief / show ipv6 interface brief.
show running-config interface <interface-id>.
show ip route / show ipv6 route.</interface-id>
How do you filter the output of show commands?
Use the pipe (|) with:
* section: Show entire section.
* include: Include matching lines.
* exclude: Exclude matching lines.
* begin: Start output from matching line.
How do you use the command history feature?
Press Ctrl+P or Up Arrow to recall older commands.
Press Ctrl+N or Down Arrow to recall newer commands.
Use show history to view the command buffer.
Adjust buffer size: terminal history size <number>.</number>
What do the following errors indicate?
Input Errors
Runts
Giants
CRC Errors
Collisions
Input Errors: Total errors on received packets.
Runts: Packets smaller than minimum size.
Giants: Packets larger than maximum size.
CRC Errors: Checksum mismatches (cable/interface issues).
Collisions: Occur in half-duplex mode (not in full-duplex).
What is an IPv6 link-local address, and when is it used?
Automatically assigned to an interface when a global unicast address is configured.
Begins with FE80.
Used for communication on the local link (e.g., neighbor discovery).
What is a local host route, and what is its purpose?
A route with a /32 (IPv4) or /128 (IPv6) mask.
Used for the router’s own IP addresses.
Allows the router to process packets destined to its interfaces.
What steps should you take to troubleshoot connectivity issues?
Verify physical connections.
Check interface status (show interfaces).
Verify IP configuration (show ip interface brief).
Check for errors (e.g., CRC, collisions).
Test connectivity (e.g., ping, traceroute).
What happens when a switch powers on?
Runs a self-test (POST)
Loads a small program (boot loader)
Sets up the CPU and flash memory
Finds and loads the IOS (operating system)
How do you tell the switch which IOS to load?
Use: boot system flash:<path-to-IOS-file></path-to-IOS-file>
What do these switch lights mean?
SYST: System is on and working
STAT: Port status (green = good)
DUPLX: Port duplex mode (full/half)
SPEED: Port speed (10/100/1000 Mbps)
PoE: Power over Ethernet status
How do you fix a switch that won’t boot?
Connect to the console
Hold the Mode button while powering on
Use boot loader commands to fix or reinstall IOS
