Module 1.2 & 1.3 Flash Cards

What is full-duplex communication?

Communication where a device can send and receive data simultaneously

What is half-duplex communication?

Communication where a device can send or receive, but not both at the same time

What is another name for full-duplex communication?

Bidirectional communication

What is a major advantage of full-duplex communication?

It allows simultaneous transmission and reception

What happens to collisions in full-duplex mode?

Collisions do not occur

What type of communication can have collisions?

Half-duplex communication

What devices commonly used half-duplex communication?

Older devices such as hubs

What is microsegmentation?

Creating a network segment with a single device connected to each switch port

What happens to the collision domain on a full-duplex switch port?

There is no collision domain

What duplex mode is required by Gigabit Ethernet?

Full-duplex

What duplex mode is required by 10 Gigabit Ethernet?

Full-duplex

What happens to collision detection in full-duplex mode?

It is disabled

What command manually sets a switch port to full-duplex?

duplex full

What command manually sets a switch port speed to 100 Mbps?

speed 100

What are the default speed and duplex settings on many Cisco Catalyst switches?

Auto speed and auto duplex

What is auto-negotiation?

A process that allows devices to automatically determine compatible speed and duplex settings

What can happen when speed or duplex settings are mismatched?

Connectivity and performance problems

What is a best practice when connecting to known devices?

Manually configure compatible speed and duplex settings when appropriate

What duplex mode do fiber-optic ports typically use?

Full-duplex

What is Auto-MDIX?

A feature that automatically detects whether a straight-through or crossover cable is needed

What command enables Auto-MDIX?

mdix auto

What cable types can be used when Auto-MDIX is enabled?

Either straight-through or crossover

What settings should be used with Auto-MDIX for proper operation?

Speed and duplex should be set to auto

What is the traditional cable for a switch-to-switch connection without Auto-MDIX?

Crossover cable

What is the traditional cable for a switch-to-PC connection without Auto-MDIX?

Straight-through cable

What command displays interface status and statistics?

show interfaces

What command displays the startup configuration?

show startup-config

What command displays the running configuration?

show running-config

What command displays flash information?

show flash

What command displays hardware and software information?

show version

What command displays previously entered commands?

show history

What command displays IPv4 interface information?

show ip interface

What command displays IPv6 interface information?

show ipv6 interface

What command displays the MAC address table?

show mac address-table

What does show running-config display?

The configuration currently running on the switch

What does show startup-config display?

The configuration saved for use after a reboot

What does show interfaces display?

Interface status, configuration, statistics, and errors

What does up/up mean on a switch interface?

The physical interface and data link protocol are both operational

What does the first up in up/up represent?

The physical layer/interface

What does the second up in up/up represent?

The data link layer/line protocol

What does up/down indicate?

The physical connection is working but there is a Layer 2 problem

What does down/down usually indicate?

A physical connection or interface problem

What does administratively down mean?

The interface was manually disabled with the shutdown command

What command manually disables an interface?

shutdown

What command enables a disabled interface?

no shutdown

What are input errors?

The total errors received by an interface

What are runts?

Ethernet frames smaller than the 64-byte minimum

What are giants?

Ethernet frames larger than the maximum allowed frame size

What do CRC errors usually indicate?

A cable, media, connection, or interference problem

What should you check when seeing many CRC errors?

Check the cable, connections, and sources of electrical noise

What are output errors?

Errors that prevent successful transmission of data out of an interface

Are collisions normal on a half-duplex connection?

Yes

Should collisions occur on a properly configured full-duplex interface?

No

What is a late collision?

A collision occurring after 512 bits of a frame have been transmitted

What commonly causes late collisions?

Excessive cable length or a duplex mismatch

What should you check first when a switch interface is down?

Cables, connectors, and possible physical damage

What should you check if a switch interface is up but connectivity is poor?

Errors, noise, cable length/type, collisions, and duplex settings

What protocol does Telnet use?

TCP

What TCP port does Telnet use?

Port 23

Is Telnet encrypted?

No

How does Telnet transmit usernames and passwords?

In plaintext

Why is Telnet insecure?

Attackers can potentially capture usernames, passwords, and transmitted data

What is SSH?

Secure Shell, a protocol for secure remote management

What TCP port does SSH use?

Port 22

Is SSH encrypted?

Yes

What is the main advantage of SSH over Telnet?

SSH encrypts authentication and transmitted data

Which should be used for secure remote management, Telnet or SSH?

SSH

What does K9 in a Cisco IOS filename indicate?

The IOS supports cryptographic/encryption features

What command checks the Cisco IOS version?

show version

What command checks whether SSH is supported and enabled?

show ip ssh

What command configures the network domain name for SSH?

ip domain-name

What command generates RSA keys for SSH?

crypto key generate rsa

What does generating RSA keys do for SSH?

It enables the SSH server and creates the RSA key pair

What is an RSA key pair used for in SSH?

Providing cryptographic security for SSH connections

What command enables SSH version 2?

ip ssh version 2

Why should SSH version 2 be used instead of SSH version 1?

SSH version 1 has known security weaknesses

What command creates a local username and encrypted password?

username secret

What are VTY lines?

Virtual terminal lines used for remote CLI connections

What command enters VTY line configuration?

line vty 0 15

What command allows only SSH connections on VTY lines?

transport input ssh

What does login local do?

Uses the local username database to authenticate remote users

What command verifies the SSH version and configuration?

show ip ssh

What command displays active SSH connections?

show ssh

What does transport input ssh prevent?

Non-SSH remote connections such as Telnet

What is the difference between Telnet and SSH?

Telnet uses TCP 23 and plaintext; SSH uses TCP 22 and encryption