Simulazione CCNA (solo errori)

What do Network Protocols define?

The rules and formats for how messages are exchanged between the source and the destination.

What is required for the Remote Management of a Layer 2 switch?

An IP address (assigned to the Switched Virtual Interface - SVI).

What are the two primary criteria for selecting a Network Medium?

1. The distance the signal can successfully travel; 2. The environment where it will be installed.

Extranet

An extended network that provides secure access to external partners or customers outside the organization.

Intranet

The private, internal network of an organization, accessible only to employees.

The computing model where server software runs on dedicated machines.

Client/Server

Which connectivity protocol uses coaxial cable as the physical medium?

Cable (Cable TV service)

Which high-bandwidth connection runs over the existing copper telephone line?

DSL (Digital Subscriber Line)

Which internet connection is "not suited for heavily wooded areas"?

Satellite (Requires clear line-of-sight)

To which Layer (and protocol) is the Port Number added?

Transport Layer (L4), protocols TCP or UDP.

Which Cisco IOS mode is protected to prevent unauthorized access to configuration commands?

Privileged EXEC mode (protected by the enable password).

Which two Cisco device access interfaces can be secured with passwords?

Console interface (local access) and VTY interface (remote Telnet/SSH access).

During Decapsulation (receiving), what is the first protocol that examines the frame?

Ethernet (Layer 2)

What is the correct order of decapsulation (bottom-up) for receiving a web page?

Ethernet, IP, TCP, HTTP

When a device sends data to a remote network (across a router), the Destination IP is that of…

…the final destination device.

When a device sends data to a remote network (across a router), the Destination MAC is that of…

…the Next-Hop (the router's interface).

Is DSL classified as a narrowband or broadband connection?

Broadband (High bandwidth).

Which layer uses MAC addresses to forward Frames on the local network?

Layer 2 (Data Link)

Which layer uses IP addresses to route Packets between different networks?

Layer 3 (Network)

Which connection type typically has very low bandwidth (max 56 Kbps)?

Dial-up telephone

User EXEC Mode

The first level of access to the CLI after login. Has limited commands (monitoring only). The prompt ends with >.

Privileged EXEC Mode

Accessed with the enable command. Allows advanced monitoring and file management commands (like copy run start). The prompt ends with #.

Global Configuration Mode

Accessed with configure terminal (from Privileged EXEC mode). Changes made here (e.g., hostname) affect the entire device.

Command: copy running-config startup-config

Saves the currently running configuration (in RAM) to the startup configuration (in NVRAM). The new config will load upon reboot.

Command: service password-encryption

Encrypts (using a weak algorithm) all clear-text passwords (e.g., console, VTY) in the configuration file to prevent them from being read with show running-config.

Key: Tab

Completes abbreviated commands or parameters. (E.g., conf t + Tab -> configure terminal)

Key: ?

Provides context-sensitive help (shows available commands or subsequent options).

Key: Ctrl-Shift-6

The "break sequence." Stops executing commands like ping or traceroute.

Key: Up Arrow

Scrolls backward through the history of previously entered commands.

Key: Space Bar

Displays the next screen when the output is long (e.g., show running-config).

Order of Encapsulation (Sending)

Data -> Segment (TCP) -> Packet (IP) -> Frame (Ethernet).

Telnet Sending (1st Step)

Telnet-formatted Data (Application) is provided to the next layer (Transport).

Telnet Sending (2nd Step)

The TCP header is added (creating a Segment).

Telnet Sending (3rd Step)

The IP header is added (creating a Packet/Datagram).

Telnet Sending (4th Step)

The Ethernet header is added (creating a Frame).

IANA (Internet Assigned Numbers Authority)

Organization responsible for IP address allocation and domain name management (DNS).

ISO (International Organization for Standardization)

The largest developer of international standards. Known for the OSI (Open Systems Interconnection) reference model.

ISOC (Internet Society)

Organization that promotes the open development, evolution, and use of the Internet globally.

Packet Destination (IP)

When sending to a remote network, the destination IP is always that of the final host (e.g., HostA).

Frame Destination (MAC)

When sending to a remote network, the destination MAC is that of the default gateway (e.g., RouterB).

RAM (Volatile Memory)

Short-term memory. Contents are lost when the device is powered off. It holds the running-config.

NVRAM (Non-Volatile Memory)

Long-term memory. Retains contents without power. It holds the startup-config.

Running Configuration

The configuration that is actively running on the device, stored in RAM.

SVI (Switched Virtual Interface)

A logical (Layer 3) interface on a Layer 2 switch that allows the switch to be assigned an IP address.

Main purpose of an SVI

To enable remote management of the switch (e.g., via SSH or Telnet).

Default SVI

Interface VLAN 1 (associated with VLAN 1 by default).

IOS Mode Order (Step 1)

User EXEC Mode (Switch>) - The starting point.

IOS Mode Order (Step 2)

Privileged EXEC Mode (Switch#) - Accessed via the enable command.

IOS Mode Order (Step 3)

Global Configuration Mode (Switch(config)#) - Accessed via the configure terminal command.

IOS Mode Order (Step 4 - Final)

Line Configuration Mode (Switch(config-line)#) - Used to configure specific lines (like console 0 or vty).