7.4.4 Module Quiz – DHCPv4 Answers
1. 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.)
2. An administrator issues the commands:
Router(config)# interface g0/1 Router(config-if)# ip address dhcp
What is the administrator trying to achieve?
- configuring the router to act as a DHCPv4 server
- configuring the router to act as a relay agent
- configuring the router to resolve IP address conflicts
- configuring the router to obtain IP parameters from a DHCPv4 server
3. When a client is requesting an initial address lease from a DHCP server, why is the DHCPREQUEST message sent as a broadcast?
- The client does not yet know the IP address of the DHCP server that sent the offer.
- The client may have received offers from multiple servers, and the broadcast serves to implicitly decline those other offers.
- The client does not have a MAC address assigned yet, so it cannot send a unicast message at Layer 2.
- The DHCP server may be on a different subnet, so the request must be sent as a broadcast.
4. Which DHCP IPv4 message contains the following information?
Destination address: 255.255.255.255
Client IPv4 address: 0.0.0.0
Default gateway address: 0.0.0.0
Subnet mask: 0.0.0.0
5. What kind of message is sent by a DHCPv4 client requesting an IP address?
- DHCPDISCOVER unicast message
- DHCPDISCOVER broadcast message
- DHCPOFFER unicast message
- DHCPACK unicast message
6. As a DHCPv4 client lease is about to expire, what is the message that the client sends the DHCP server?
7. What is the destination IP address when an IPv4 host sends a DHCPDISCOVER message?
8. If more than one DHCP server is available on the local network, in which order will DHCP messages be sent between a host and a DHCP server?
- acknowledgment, request, offer, discover
- request, discover, offer, acknowledgment
- discover, offer, request, acknowledgment
- request, acknowledgment, discover, offer
9. What is the most likely scenario in which the WAN interface of a router would be configured as a DHCP client to be assigned a dynamic IP address from an ISP?
- There is a web server for public access on the LAN that is attached to the router.
- The router is configured as a DHCP server.
- The router is also the gateway for a LAN.
- It is a SOHO or home broadband router.
10. Which is a DHCPv4 address allocation method that assigns IPv4 addresses for a limited lease period?
- manual allocation
- dynamic allocation
- automatic allocation
11. What is the reason why the DHCPREQUEST message is sent as a broadcast during the DHCPv4 process?
- for routers to fill their routing tables with this new information
- to notify other hosts not to request the same IP address
- for hosts on other subnets to receive the information
- to notify other DHCP servers on the subnet that the IP address was leased
12. How is a DHCPDISCOVER transmitted on a network to reach a DHCP server?
- A DHCPDISCOVER message is sent with the IP address of the default gateway as the destination address.
- A DHCPDISCOVER message is sent with a multicast IP address that all DHCP servers listen to as the destination address.
- A DHCPDISCOVER message is sent with the broadcast IP address as the destination address.
- A DHCPDISCOVER message is sent with the IP address of the DHCP server as the destination address.
13. Which destination IPv4 address does a DHCPv4 client use to send the initial DHCP Discover packet when the client is looking for a DHCP server?
- the IP address of the default gateway
14. Under which two circumstances would a router usually be configured as a DHCPv4 client? (Choose two.)
- This is an ISP requirement.
- The administrator needs the router to act as a relay agent.
- The router is meant to provide IP addresses to the hosts.
- The router is intended to be used as a SOHO gateway.
- The router has a fixed IP address.
15. Which address does a DHCPv4 server target when sending a DHCPOFFER message to a client that makes an address request?
- broadcast MAC address
- client hardware address
- gateway IP address
- client IP address
16. Which DHCPv4 message will a client send to accept an IPv4 address that is offered by a DHCP server?
- Broadcast DHCPACK
- Broadcast DHCPREQUEST
- Unicast DHCPACK
- Unicast DHCPREQUEST
17. What is an advantage of configuring a Cisco router as a relay agent?
- It can forward both broadcast and multicast messages on behalf of clients.
- It can provide relay services for multiple UDP services.
- It reduces the response time from a DHCP server.
- It will allow DHCPDISCOVER messages to pass without alteration
18. A host on the 10.10.100.0/24 LAN is not being assigned an IPv4 address by an enterprise DHCP server with the address 10.10.200.10/24. What is the best way for the network engineer to resolve this problem?
- Issue the default-router 10.10.200.10 command at the DHCP configuration prompt on the 10.10.100.0/24 LAN gateway router.
- Issue the ip helper-address 10.10.100.0 command on the router interface that is the 10.10.200.0/24 gateway.
- Issue the ip helper-address 10.10.200.10 command on the router interface that is the 10.10.100.0/24 gateway.
- Issue the network 10.10.200.0 255.255.255.0 command at the DHCP configuration prompt on the 10.10.100.0/24 LAN gateway router.
19. What is accomplished by the ip dhcp excluded-address 10.10.4.1 10.10.4.5 command?
- The DHCP server will ignore all traffic from clients with IPv4 addresses 10.10.4.1 to 10.10.4.5.
- The DHCP server will not issue IPv4 addresses ranging from 10.10.4.1 to 10.10.4.5.
- Traffic destined for 10.10.4.1 to 10.10.4.5 will be denied.
- Traffic from clients with IPv4 addresses 10.10.4.1 to 10.10.4.5 will be denied.
20. Which Windows command combination would enable a DHCPv4 client to reinstate its IPv4 configuration?
- Enter ip config /release and then ip config /autonegotiate
- Enter ip config /release and then ip config /renew
- Enter ipconfig /release and then ipconfig /autonegotiate
- Enter ipconfig /release and then ipconfig /renew
21. Which command issued on R1 can be used to verify the current IPv4 address and MAC address binding?
- R1# show ip dhcp binding
- R1# show ip dhcp pool
- R1# show ip dhcp server statistics
- R1# show running-config | section dhcp
22. Which DHCP operation statement is true?
- A DHCP client must wait for lease expiration before sending a new DHCPREQUEST message.
- If a DHCP client receives several DHCPOFFER messages from different servers, it sends a unicast DHCPACK message to the selected server.
- The DHCPDISCOVER message contains the IPv4 address and subnet mask to be assigned, the IPv4 address of the DNS server, and the IPv4 address of the default gateway.
- When a DHCP client boots, it broadcasts a DHCPDISCOVER message to identify an available DHCP server on the network.