4th SLÜ

Question 1

Which message is sent by a DHCPv4 client to initiate the lease obtaining process?

Answer 1

DHCPDISCOVER
Explanation: DHCPv4 clients initiate the lease process by sending a DHCPDISCOVER message as a broadcast onto the network to locate a DHCPv4 server.

Question 2

Which two DHCPv4 messages are sent by the server in the lease obtaining process? (Choose two.)

Answer 2

DHCPOFFER
DHCPACK

Explanation: DCHPv4 servers send two messages in the lease origination process, the DHCPOFFER and the DHCPACK.

Question 3

Which two DHCPv4 messages are used in the lease renewal process? (Choose two.)

Answer 3

DHCPREQUEST
DHCPACK
Explanation: The lease renewal process involves two messages. The client sends a DHCPREQUEST and the server responds with a DHCPAK.

Question 4

Describe the steps necessary to configure a router as a dhcp client.

Answer 4

Enter interface configuration mode. Use g0/0/1 as the interface name.
SOHO(config)#interface g0/0/1

Configure the interface to acquire IPv4 addressing information from the ISP.
SOHO(config-if)#ip address dhcp

Activate the interface.
SOHO(config-if)#no shutdown

Sep 12 10:01:25.773: %DHCP-6-ADDRESS_ASSIGN: Interface GigabitEthernet0/0/1 assigned DHCP address 209.165.201.12, mask 255.255.255.224, hostname SOHO

Return to privileged EXEC mode.
SOHO(config-if)#end

Use the show ip interface g0/0/1 command to verify the IPv4 information.
SOHO#show ip interface g0/0/1

GigabitEthernet0/0/1 is up, line protocol is up
Internet address is 209.165.201.12/27
Broadcast address is 255.255.255.255
Address determined by DHCP
(output omitted)

You have successfully configured the router as a DHCP client.

Question 5

A DHCP-enabled client PC has just booted. During which two steps will the client PC use broadcast messages when communicating with a DHCP server? (Choose two.)

Answer 5

DHCPDISCOVER
DHCPREQUEST

All DHCP messages between a DHCP-enabled client and a DHCP server are using broadcast messages until after the DHCPACK message. The DHCPDISCOVER and DHCPREQUEST messages are the only messages that are sent by a DHCP-enabled client. All DHCP messages between a DHCP-enabled client and a DHCP server use broadcast messages when the client is obtaining a lease for the first time.

Question 6

An administrator issues the commands:

Router(config)# interface g0/1
Router(config-if)# ip address dhcp

What is the administrator trying to achieve?

Answer 6

configuring the router to obtain the IP parameters from a DHCPv4 server

The ip address dhcp command activates the DHCPv4 client on a given interface. By doing this, the router will obtain the IP parameters from a DHCPv4 server.

Question 7

When a client is requesting an initial address lease from a DHCP server, why is the DHCPREQUEST message sent as a broadcast?

Answer 7

The client may have received offers from multiple servers, and the broadcast serves to implicitly decline those other offers.

During the initial DHCP exchange between a client and server, the client broadcasts a DHCPDISCOVER message looking for DHCP servers. Multiple servers may be configured to respond to this request with DHCPOFFER messages. The client will choose the lease from one of the servers by sending a DHCPREQUEST message. It sends this message as a broadcast so that the other DHCP servers that sent offers will know that their offers were declined and the corresponding address can go back into the pool.