CHAPTER 10 DHCP - Dynamic Host Configuration Protocol
DHCP release
can be used optionally to return and terminate an IP address
What three address locations does DHCPV4 use
-Manual Allocation -Automatic Allocation -Dynamic Allocation
Under which two circumstances would a router usually be configured as a DHCPv4 client? (Choose two.)
-The router is intended to be used as a SOHO gateway. -This is an ISP requirement.
Discovery
The client queries the server at address 255.255.255.255 with DHCP****
A company uses DHCP servers to dynamically assign IPv4 addresses to employee workstations. The address lease duration is set as 5 days. An employee returns to the office after an absence of one week. When the employee boots the workstation, it sends a message to obtain an IP address. Which Layer 2 and Layer 3 destination addresses will the message contain?
FF-FF-FF-FF-FF-FF and 255.255.255.255
What protocol does SLAAC use?
ICMP
Which protocol supports Stateless Address Autoconfiguration (SLAAC) for dynamic assignment of IPv6 addresses to a host?
ICMPv6
Acknowledgement
Once the server receives DHCPREQUEST it will respond with DHCP****. Once the client receives that packet of data, it will probe the new IP to ensure there are no conflicts.
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 obtain IP parameters from a DHCPv4 server
A company uses the SLAAC method to configure IPv6 addresses for the employee workstations. Which address will a client use as its default gateway?​
the link-local address of the router interface that is attached to the network
Type a command to exclude the first fifteen useable IP addresses from a DHCPv4 address pool of the network 10.0.15.0/24.
excluded-address 10.0.15.1 10.0.15.15
What makes DHCP reliable?
By allowing renewing leases that have an end
A network administrator is implementing DHCPv6 for the company. The administrator configures a router to send RA messages with M flag as 1 by using the interface command ipv6 nd managed-config-flag. What effect will this configuration have on the operation of the clients?
Clients must use all configuration information that is provided by a DHCPv6 server.
What is the main goal of DHCP?
To dynamically assigning network configurations to hosts such as assigning IPs on IP networks
Why is DHCPREQUEST periodically resent?
To see is a server is still online or is down
What type and how many ports does DHCP use?
Two UDP ports: 67 and 68
What is used for long distance assignments?
big routers to repeaters
Which DHCPv4 message will a client send to accept an IPv4 address that is offered by a DHCP server?
broadcast DHCPREQUEST
DHCP inform
can be used if the client wants additional DHCP information after DORA
Which is a DHCPv4 address allocation method that assigns IPv4 addresses for a limited lease period?
dynamic allocation
Why does DHCP use broadcast?
to notify other DHCP servers on the subnet that the IP address was leased
What is SLACC
A method in which a device can obtain a global IPv6 Unicast address without the services of a DHCPv6 server.
Static Allocation
A particular IP address is pre-allocated to a single device by an administrator. DHCP only communicates the IP address to the device.
Define the stage of DHCP
Acts according to DORA -Discover -Offer -Request -Acknowledgement
A network engineer is troubleshooting hosts on a LAN that are not being assigned an IPv4 address from a DHCP server after a new Ethernet switch has been installed on the LAN. The configuration of the DHCP server has been confirmed as correct and the clients have network connectivity to other networks if a static IP address is configured on each one. What step should the engineer take next to solve the issue?
Confirm that ports on the Layer 2 LAN switch are configured as edge ports.
Dynamic Allocation
DHCP assigns an IP address from a pool of address for a limited period of time chosen by the server, or until the client tells the DHCP server that it no longer needs the address
Automatic Allocation
DHCP automatically assigns an IP address permanently to a device, selecting it from a pool of available addresses.
What happens if renewal is not possible?
DHCPDISCOVER will be broadcast so that a new IP address can be assigned.
What does clients periodically send through unicast?
DHCPREQUEST
What happens if a server remains down?
DHCPREQUEST will be broadcast in the hopes that another server can renew the IP lease.
A company implements the stateless DHCPv6 method for configuring IPv6 addresses on employee workstations. After a workstation receives messages from multiple DHCPv6 servers to indicate their availability for DHCPv6 service, which message does it send to a server for configuration information?
DHCPv6 INFORMATION-REQUEST
What are the parameters set by the DHCP server for a device requesting an address?
Default Gateway Domain Name Name Servers Time Servers
What are the steps to configure a router as a DHCP server?
Define excluded addresses. Configure a DHCP pool. Default Router
Which is a DHCPv4 address allocation method that assigns IPv4 addresses for a limited lease period?
Dynamic Allocation
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 command ip helper-address 10.10.200.10 on the router interface that is the 10.10.100.0/24 gateway.
Request
If a client received offers from multiple servers, it will select an offer and request that IP with DHCP****. It will also alert the other servers of which offer it accepted. The other servers will terminate their offers
A network administrator configures a router to send RA messages with M flag as 0 and O flag as 1. Which statement describes the effect of this configuration when a PC tries to configure its IPv6 address?
It should use the information that is contained in the RA message and contact a DHCPv6 server for additional information.
A company uses the method SLAAC to configure IPv6 addresses for the workstations of the employees. A network administrator configured the IPv6 address on the LAN interface of the router. The interface status is UP. However, the workstations on the LAN segment did not obtain the correct prefix and prefix length. What else should be configured on the router that is attached to the LAN segment for the workstations to obtain the information?​
R1(config)# ipv6 unicast-routing
This is pre-configured.
Static
Refer to the exhibit. A network administrator is implementing the stateless DHCPv6 operation for the company. Clients are configuring IPv6 addresses as expected. However, the clients are not getting the DNS server address and the domain name information configured in the DHCP pool. What could be the cause of the problem?CCNA2_Ch10_02
The router is configured for SLAAC DHCPv6 operation.
Refer to the exhibit. A network administrator is implementing stateful DHCPv6 operation for the company. However, the clients are not using the prefix and prefix-length information that is configured in the DHCP pool. The administrator issues a show ipv6 interface command. What could be the cause of the problem?CCNA2_Ch10_01
The router is configured for stateless DHCPv6 operation.
Offer
The server responds with DHCP**** which includes the clients MAC address, offered IP, subnet mask, lease duration, and the IP of the server making the offer
Where can a client find available optional settings?
Through DHCP and BOOT PARAMETERS
Define the "lease"
a set duration is allowed for a device, which can be reassigned or altered at the end of one
Which set of commands will configure a router as a DHCP server that will assign IPv4 addresses to the 192.168.100.0/23 LAN while reserving the first 10 and the last addresses for static assignment?
ip dhcp excluded-address 192.168.100.1 192.168.100.10 ip dhcp excluded-address 192.168.101.254 ip dhcp pool LAN-POOL-100 network 192.168.100.0 255.255.254.0 default-router 192.168.100.1
An administrator wants to configure hosts to automatically assign IPv6 addresses to themselves by the use of Router Advertisement messages, but also to obtain the DNS server address from a DHCPv6 server. Which address assignment method should be configured?
stateless DHCPv6
