Network+ Chapter 5

Which type of server in your network uses pointer and A records? NAT Translation server IPS/IDS Server DNS Server Proxy Server

A DNS server uses many types of records. An "A" record is a hostname to IP address record and a pointer record is an IP address to hostname record.

Which device should be used if you need to send incoming packets to one or more machines that are hidden behind a single IP address? Switch Load balancer Hub Repeater

A load balancer uses a little trickery and sends incoming packets to one or more machines that are hidden behind a single IP address. Modern load-balancing routers can use different rules to make decisions about where to route traffic, which can be based on least load, fastest response times, or simply balancing requests.

Users on your network are saturating your bandwidth because they are using too many nonwork related sites. What device would limit the availability of the types of sites that users on a LAN have access to while providing granular control over the traffic between the local LAN and the Internet? Switch DHCP server DNS server Proxy server

A proxy server can provide many functions. A proxy server can use a caching engine so repeated access request for web information would accelerate repeated access for users, and they can also limit the availability of web sites.

Which of the following devices can work at both Layers 2 and 3 of the OSI model? Hub Switch Repeater Bridge

A switch is typically just a Layer 2 device segmenting the network by using MAC addresses. However, some higher‐end switches can provide Layer 3 services

What advantage does a switch have over a hub? It discards frames. Transmissions received on one port will be sent out all the other ports. It recognizes frame boundaries and destination MAC addresses of incoming frames. Any two or more devices the switch connects have the capability of causing a collision with each other.

A switch recognizes frame boundaries and pays attention to the destination MAC address of the incoming frame as well as the port on which it was received.

Which device is used to segment a network? Hub Switch Repeater All of the above

A switch. Hubs don't segment a network; they just connect network segments together. Repeaters don't segment the network; they repeat a signal and allow the distance covered to be increased.

You need a device that detects and reports attempts of unauthorized access to your network, identifies suspicious activity, and is best for identifying an attack. Which device should you install? Firewall IDS IPS Proxy server

An IDS device can detect and report suspicious activity, but unlike an IPS, it does not stop attacks. IDS is best for identifying an attack.

This device uses hardware addresses to filter a network

Bridge or Switch

What role does the "A" record in a Domain Name Service (DNS) server have in your network? Translates human name to IP address Translates IP address to human name Enables printing, copying, and faxing from one device Controls network packets to optimize performance

DNS translates human names to IP addresses for routing your packet through the Internet.

Hardware addresses are defined at this layer

Data Link (MAC Sublayer)

Ethernet is defined at these layers

Data Link and Physical

What is the function of a firewall? Protects LAN resources from attackers on the Internet Provides extra bandwidth Reduces throughput Allows access to all computers on a LAN

Firewalls are the first line of defense for an Internet-connected network. If a network was directly connected to the Internet without a firewall, an attacker could theoretically gain direct access to the computers and servers on that network with little effort.

This device creates one big collision domain and one large broadcast domain

HUB

This device can never run full duplex

Hub

A network device that is used to connect multiple devices together without segmenting a network is a? Hub Wireless access point Switch Router

Hubs create one collision domain and one broadcast domain

Which device does not aid in network segmentation? Router Switch Hub Bridge

Hubs don't segment networks, they just connect network segments together.

Users arrive at the office after a weekend and the hosts that were shut down over the weekend are restarted but cannot access the LAN or Internet. Hosts that were not shut down are working fine. Where can the problem be? The DNS server The DHCP server The Proxy server The Firewall

If the DHCP server has stopped functioning, it will not hand out IP addresses to hosts that are restarted. However, the hosts that were not shut down still have an IP addresses because the lease time has not expired.

Logical addressing is used at this layer

Network

What is an advantage of using DHCP in a network environment? More difficult administration of the network Static IP addressing Can send an operating system for the PC to boot from Assigns IP address to hosts

Remember that DHCP servers assign IP addresses to hosts. Thus DHCP allows easier administration than providing IP information to each host by hand (called static IP addressing).

A layer‐3 switch or multilayer switch

Router

This device breaks up collision domains and broadcast domains

Router

This device can measure the distance to a remote network

Router

This device sends and receives information about the Network layer.

Router

Which device by default does not forward any broadcast or multicast packets? Repeater Hub Router Switch

Routers don't forward any broadcast or multicast packets by default, but they do have plenty of other functions like using the logical address, using access lists, and providing Layer 2 bridging functions.

This device creates many smaller collision domains, but the network is still one large broadcast domain

Switch or Bridge

Which device creates separate collision domains and a single broadcast domain? Hub Router Switch Modem

Switches create separate collision domains but a single broadcast domain. Remember that routers provide a separate broadcast domain for each interface.

This layer supports flow control and sequencing

Tansport

Which is not a common term associated with modems? POTS DSL Cable NIC

The NIC is the expansion card you install in your computer to connect, or interface, your computer to the network.

Which is not an advantage of network segmentation? Reduced congestion Improved security Containing network problems Preventing broadcast storms

The first 3 options all aid in boosting network performance, so the only option left is broadcast storms. Increased traffic will increase LAN congestion

What is the primary function of a bridge? Breaks up collision domains Allows a NIC or other networking device to connect to a different type of media than it was designed for Allows mobile users to connect to a wired network wirelessly None of the above

The primary function of a bridge is to keep traffic separated on both sides of the bridge, breaking up collision domains

What is a benefit of a multilayer switch (MLS) over a Layer 2 switch? Less bandwidth Routing functions Fewer features Fewer ports

They allow routing functions between subnets.

This layer creates a virtual circuit before transmitting between two end stations.

Transport

What is the most common use for a web proxy? Web cache Increases throughput Provides administrative control Supports user authentication

Web cache, of course! Most proxy programs provide a means to deny access to certain URLs in a blacklist, thus providing content filtering, usually in corporate environments.