Module 1 Flashcards
What command is useful for detecting common media issues in switch interfaces?
show interfaces
Displays line and data link protocol status.
What does ‘FastEthernet0/18 is up’ indicate?
The hardware layer is operational, receiving a carrier detect signal.
What does ‘line protocol is up’ signify?
The data link layer protocol keepalives are being received.
If the interface is up but the line protocol is down, what could be the potential issues?
- Encapsulation type mismatch
- Interface on the other end is error-disabled
- Hardware problem
What does it mean if both the line protocol and the interface are down?
A cable is not attached or another interface problem exists.
What does an administratively down interface indicate?
It has been manually disabled using the shutdown command.
Which command verifies that the switch has been correctly configured?
show running-config
What command displays the interface status and configuration?
show interfaces [interface-id]
What does auto-MDIX do?
Automatically detects required cable connection type and configures it.
What types of cables are used when auto-MDIX is not available?
- Straight-through cables for servers, workstations, or routers
- Crossover cables for switches or repeaters
What command enables auto-MDIX on a newer Cisco switch?
mdix auto
What must be set for the auto-MDIX feature to operate correctly?
Interface speed and duplex must be set to auto.
What command is used to examine the auto-MDIX setting for a specific interface?
show controllers ethernet-controller [phy] with include Auto-MDIX
What is the default setting for duplex and speed on Cisco Catalyst 2960 and 3560 switches?
auto
What is the maximum mode for 10/100/1000 ports when set to 1000 Mbps?
Only full-duplex mode.
What should be done when troubleshooting switch port issues?
Check duplex and speed settings.
What is the consequence of mismatched duplex settings?
Connectivity issues may arise.
What is full-duplex communication?
Allows both ends to transmit and receive data simultaneously.
What does a microsegmented LAN require?
A switch port with only one device connected and operating in full-duplex mode.
What is the effect of half-duplex communication?
Creates performance issues due to unidirectional data flow.
What command shows the summary of all interfaces and their status?
show ip interface brief
What command is used to verify that SSH is operational?
show ip ssh
What does the boot system command do?
Reboots all modules in switch and allows user to specify what image to use.
What are the steps in the boot sequence of a Cisco switch?
- Load POST program
- Load boot loader software
- Initialize CPU
- Initialize flash file system
- Load IOS
What is the purpose of the VLAN interface configuration?
To create a virtual network segment within a physical network.
What does the System LED (SYST) indicate?
Whether the system is receiving power and functioning properly.
What does a green Port Speed LED (SPEED) indicate?
Port speed mode is selected.
What does a green LED indicate on a switch?
Port speed mode is selected
The light associated with each port shows the port speed.
What does a blinking amber LED indicate on a switch?
Port blocked preventing loop
This indicates a network issue that prevents data transmission.
What is the purpose of the Mode button on a switch?
To move between different modes – STAT, DUPLX, SPEED, and PoE
Each mode provides different operational information.
What is indicated by the amber LED under the PoE status?
PoE off due to fault
This indicates that there is an issue with the Power over Ethernet functionality.
What command provides access to the boot loader on a switch?
Press and hold the Mode button while reconnecting power
This allows access to recover from system crashes.
What is the first step in recovering from a system crash on a switch?
Connect a PC by console cable to the switch console port
Terminal emulation software must be configured to connect.
What command is used to configure the default gateway on a switch?
ip default-gateway 172.17.99.1
This command sets the gateway for remote management access.
What is the purpose of the switch virtual interface (SVI)?
To manage the switch from a remote network
The SVI allows for IP address assignment separate from physical ports.
What must be configured for the management VLAN to be secure?
Use a VLAN other than VLAN 1 for management
VLAN 1 is the default and is considered less secure.
What command displays the command history in a switch?
show history
Displays previously executed commands for easy recall.
True or False: SSH uses TCP port 23.
False
SSH uses TCP port 22 for secure connections.
What command verifies that the switch supports SSH?
show ip ssh
This command checks for SSH capability on the switch.
Fill in the blank: To enable SSH, the switch must be configured with a unique _______.
[hostname]
A unique hostname is necessary for SSH configuration.
What does the command ‘crypto key generate rsa’ do?
Enables SSH and generates an RSA key pair
This is a crucial step in setting up SSH on the switch.
What type of errors does ‘Input Errors’ include?
- Runts
- Giants
- CRC errors
- No buffer
- Frame
- Overrun
- Ignored counts
These errors indicate issues with incoming packets.
What is a ‘runt’ frame?
An Ethernet frame smaller than 64 bytes
Typically caused by malfunctioning NICs or collisions.
What indicates a ‘giant’ frame?
An Ethernet frame larger than 1518 bytes
Giants are discarded due to exceeding the maximum size.
What command displays interface information and packet flow count?
show interfaces
This command provides statistics for all interfaces on the device.
What is the administrative distance of a local host route?
0
Local host routes are prioritized due to their administrative distance.
What command displays the IPv4 and IPv6 related information for all interfaces on a router?
show ip interface and show ipv6 interface
What command reveals the three directly connected network entries and the three local host route interface entries?
show ip route and show ipv6 route
What is the administrative distance of the local host route?
0
What masks are associated with the local host route for IPv4 and IPv6?
/32 for IPv4 and /128 for IPv6
What does a ‘C’ next to a route in the routing table indicate?
It indicates a directly connected network
What determines if an IPv6 prefix is added to the IPv6 routing table as a connected route?
The router interface must be configured with a global unicast address and be in the ‘up/up’ state
What command allows you to specify the number of lines to be displayed in the output?
terminal length
What does the pipe (|) character do when used with show commands?
It enables filtering of the command output
List the four filtering parameters that can be configured after the pipe.
- section
- include
- exclude
- begin
What type of address is automatically added to an interface whenever a global unicast address is assigned?
Link-local address
What command displays the interface status and all IPv6 addresses belonging to the interface?
show ipv6 interface gigabitethernet 0/0/0
What commands can be used to quickly reveal the status of all interfaces on a router?
show ip interface brief and show ipv6 interface brief
What indicates a problem with the router configuration or cabling?
A status of ‘down’ or protocol of ‘down’
What command displays the commands applied to a specified interface?
show running-config interface interface-id
What is required for an interface to be available on a router?
- Configured with at least one IP address
- Activated using the no shutdown command
- Connected to another device
What is a loopback interface?
A logical interface internal to the router, not assigned to a physical port
What state is the loopback interface automatically placed in as long as the router is functioning?
up
What is a common use for loopback interfaces?
Testing and managing a Cisco IOS device
How do you enable and assign a loopback address?
Router(config)# interface loopback number
Router(config-if)# ip address ip-address subnet-mask
What command shows counters and statistics for a specific interface?
show interfaces