Your manager asks you which service is responsible for translating the source IP address of a packet to the IP address of the public interface on the router.

• DHCP

• NAT

• DNS

• HTTP

Answer explanation

NAT is responsible for translating the source IP address of a packet to use the IP of the public interface on the NAT device.

You are troubleshooting a communication problem. You seem to be able to communicate with Glen’s website by IP address, but not by the fully qualified domain name (www.gleneclarke.com). What is most likely the problem?

• DHCP

• NAT

• DNS

• HTTP

Answer explanation

If you can communicate with a system by the IP address but not the FQDN, it’s a classic indication that the name is not able to resolve to an IP address. This is a sign that there is a problem with the DNS.

Which network service can be configured on your router that is responsible for assigning IP addresses to systems on the network?

• DHCP

• NAT

• DNS

• HTTP

Answer explanation

The DHCP service is responsible for assigning IP addresses automatically to systems on the network.

What service on the network is responsible for converting the FQDN to an IP address?

• Authentication server

• DNS server

• DHCP server

• NAT

Answer explanation

DNS is responsible for converting the friendly name, such as www.gleneclarke.com, to an IP address.

What service on the network is responsible for verifying username and passwords when the user attempts to log on?

• Authentication server

• DNS server

• DHCP server

• NAT

Answer explanation

An authentication server is responsible for verifying the username and passwords of clients wishing to access the network.

You are monitoring network traffic and you notice a number of DHCP discover messages on the network. Which of the following is the destination address of the DHCP discover message?

• 0F-1B-3C-2F-3C-2A

• FF-FF-FF-FF-FF-FF

• 192.168.4.5

• 192.168.0.0

Answer explanation

The DHCP discover message is a broadcast message which is used to locate the DHCP server on the network. FF-FF-FF-FF-FF-FF is the layer-2 representation of a broadcast address.

When a client system boots up and requests an IP address, it first must send out which message?

• DHCP request

• DHCP discover

• DHCP response

• DHCP ACK

Answer explanation

The DHCP discover message is the first message sent out by a DHCP client to locate a DHCP server on the network. The DHCP discover message is a broadcast message which has a destination MAC address of FF-FF-FF-FF-FF-FF

What device is responsible for regenerating the signal so that the signal can travel a greater distance?

• Bridge

• Router

• Repeater

• Switch

• Hub

Answer explanation

A repeater is a layer-1 device that is responsible for regenerating the signal.

Which device filters traffic by looking at the destination address of the frame and then forwards the frame to the port that the destination system resides on?

• Hub

• Router

• Repeater

• Switch

Answer explanation

A switch is a layer-2 device that filters traffic based off the destination MAC address of the frame.

Which of the following is a layer-3 device?

• Bridge

• Router

• Repeater

• Switch

• Hub

Answer explanation

A router is an example of a layer-3 device and is responsible for sending or receiving information to and from the network.