Unit 4 CompTIA+ Networking

For Networking

What layers of the OSI model does Ethernet operate in?

Physical and Data Link layers (layers 1 and 2).

What function does the Network layer (layer 3) provide?

Logical network addressing and forwarding.

What key fields are included in the IPv4 datagram header?

Source and destination addresses, version, length fields, and protocol field.

Which protocol uses the value 6 in the Protocol field of an IPv4 header?

Transmission Control Protocol (TCP).

Which protocol uses the value 17 in the Protocol field of an IPv4 header?

User Datagram Protocol (UDP).

What is the role of the Internet Control Message Protocol (ICMP)?

Used for status messaging and connectivity testing.

What does the Address Resolution Protocol (ARP) do?

Resolves an IPv4 address to a hardware MAC address.

What is the purpose of a default gateway?

To route packets from one network to another.

What type of addressing is used to send packets to a single recipient?

Unicast addressing.

What address is used to communicate with all hosts in a subnet?

Broadcast address.

How are multicast packets delivered in IP networking?

To a specific multicast group via a special range of IP addresses.

What is the range of IPv4 addresses used for multicast addressing?

224.0.0.0 to 239.255.255.255.

How is anycast addressing defined?

A group of hosts configured with the same IP address, with packets routed to the nearest host.

What does a 32-bit IPv4 address represent?

A combination of a network number (Network ID) and a host number (Host ID).

What is the dotted decimal notation of the IPv4 address 11000110 00110011 01100100 00000001?

198.51.100.1.

What is a subnet mask used for in an IP address?

To distinguish between the network ID and the host ID.

What does the prefix notation /24 indicate in an IP address?

That the first 24 bits are part of the network ID.

What must each host address on an IP network be?

Unique.

What is the significance of the loopback address?

Used to verify that TCP/IP is correctly installed on the local host.

What does the ipconfig command do in Windows?

Displays the IP address, subnet mask, and default gateway for network interfaces.

How does a host determine if it needs to use the default gateway or a local connection?

By comparing masked portions of the source and destination IP addresses.

What is a broadcast address in an IP network?

The last address in any IP network or subnet where all host bits are set to 1.

What is the primary purpose of DHCP?

To dynamically assign IP addresses to hosts on a network.

What kind of IP addressing allows devices to share the same IP address?

Anycast addressing.

What do you call the protocol that uses a unique address for sending packets to all interested listeners in a group?

Multicast.

What does the subnet mask 255.255.255.240 allow for in terms of hosts per subnet?

16 usable addresses (14 hosts after accounting for network and broadcast addresses).

What are the two important components of an IPv4 address?

Network ID and Host ID.

What happens when two hosts have duplicate IP addresses?

They may experience communication issues as they contend for responses.

What do the first octets of IP addresses indicate in classful addressing?

The class of the IP address (Class A, B, C, etc.).

What is the range of Class A private addresses according to RFC 1918?

10.0.0.0 to 10.255.255.255.

Why is the Network Address Translation (NAT) used?

To translate between public and private IP addresses.

What is the function of the Internet Group Management Protocol (IGMP)?

To manage multicast group memberships.

What is the role of the Default Gateway in an IP network?

To route packets from a local subnet to remote networks.

What command in Windows checks the network interface configuration including DHCP?

ipconfig /all.

What does a device using NAT do?

Translates private IP addresses to a public IP and vice versa.

How does a router use ARP for its Ethernet interfaces?

To resolve MAC addresses for IP addresses in the local segment.

What does the last address in a subnet represent?

The broadcast address.

What does the maximum theoretical size of an IPv4 packet suggest about fragmentation?

Actual packet sizes are typically smaller than 65,535 bytes to avoid fragmentation.

What is the range of IPv4 addresses that are reserved for documentation and examples?

192.0.2.0/24, 198.51.100.0/24, 203.0.113.0/24.

What is the purpose of Variable Length Subnet Masking (VLSM)?

To use different subnet masks for different subnets in an IP network.

What kind of addressing does IGMP relate to?

Multicast addressing.

How does a host identify itself on the local link in IPv6?

Through link-local addressing with a prefix of fe80::/10.

What is the significance of the address range 127.0.0.0 to 127.255.255.255?

It is reserved for loopback addressing.

What technique does IPv6 use to replace ARP?

Neighbor Discovery Protocol (ND).

What command can be used in Linux to show the current IP address configuration?

ip addr.

What does the prefix /48 represent in IPv6?

Indicates a network address from which subnets can be derived.

What is the default route or gateway used for?

To direct packets to a different network when the destination is unreachable locally.

What is the primary purpose of the ping command in network troubleshooting?

To test connectivity between devices over an IP network.

What type of configuration tasks can be performed using netsh in Windows?

View and manage network interface configurations.

What does the command netsh interface ip show config do?

Displays the current IP configuration for each network interface.

What data does an ARP table hold?

A mapping of IP addresses to MAC addresses on the local network.

What type of address does a router use to send packets to the external Internet?

Public IP address.

What happens during the process of subnetting?

Dividing a larger network into smaller, more manageable subnetworks.

What is indicated by the presence of multiple loopback addresses in a system?

Multiple loopback interfaces could be configured for different processes or services.

What must be done if a host's MAC address is found to be duplicated?

Each host must be reconfigured to ensure unique MAC addresses.

What command can diagnose local addressing issues on Windows?

arp -a.