Module 7 Flashcards
What command displays the TCP/IP parameters on a PC?
ipconfig /all
What is the purpose of the command ‘show ip dhcp server statistics’?
Displays count information regarding the number of DHCPv4 messages that have been sent and received
How can you verify DHCPv4 bindings?
Using the command ‘show ip dhcp binding’
What command shows the DHCPv4 commands configured on a router?
show running-config | section dhcp
True or False: The DHCPv4 service is enabled by default on Cisco routers.
True
What command is used to disable the DHCPv4 service?
no service dhcp
What is the function of the ‘ip helper-address’ command?
Configures the router to relay DHCPv4 messages to the DHCPv4 server
List the eight UDP services that the ‘ip helper-address’ command forwards by default.
- Port 37: Time
- Port 49: TACACS
- Port 53: DNS
- Port 67: DHCP/BOOTP server
- Port 68: DHCP/BOOTP client
- Port 69: TFTP
- Port 137: NetBIOS name service
- Port 138: NetBIOS datagram service
What command is used to configure an Ethernet interface as a DHCP client?
ip address dhcp
What do home routers typically do regarding IPv4 addressing?
Receive IPv4 addressing information automatically from the ISP
What command is used to exclude IPv4 addresses from being assigned by the DHCP server?
ip dhcp excluded-address low-address [high-address]
What is the first step in configuring a Cisco IOS DHCPv4 server?
Exclude IPv4 addresses
What command defines a DHCPv4 pool name?
ip dhcp pool pool-name
Fill in the blank: The DHCPv4 lease process starts with the client sending a _______ message.
DHCPDISCOVER
What is the last step in the DHCPv4 lease process?
DHCPACK
What happens when a DHCPv4 lease expires?
The DHCP server returns the address to the pool for reallocation
How often must clients contact the DHCP server to extend their lease?
Periodically
What command can be used to verify the configuration of the DHCP relay agent?
show ip interface
What does the command ‘lease {days [hours [minutes]] | infinite}’ do?
Defines the duration of the DHCP lease
What is the purpose of the ‘default-router’ command in DHCP configuration?
Defines the default gateway router
True or False: A dedicated DHCPv4 server is necessary for all network configurations.
False
What is the benefit of using DHCPv4 in network administration?
Saves time by dynamically assigning IP addresses and managing configurations
What does the command ‘dns-server address [address2 … address8]’ do?
Defines the DNS server for DHCP clients
What is the typical lease duration for DHCPv4 addresses?
Anywhere from 24 hours to a week or more
Lease duration can be configured by administrators.
What are the four steps a client follows to obtain a DHCPv4 lease?
- DHCP Discover (DHCPDISCOVER)
- DHCP Offer (DHCPOFFER)
- DHCP Request (DHCPREQUEST)
- DHCP Acknowledgment (DHCPACK)
This process is initiated when the client boots or wants to join a network.
What is the first step in the DHCPv4 lease renewal process?
DHCP Request (DHCPREQUEST)
The client sends this message to the original DHCPv4 server before the lease expires.
What happens if a DHCPACK is not received after sending a DHCPREQUEST during lease renewal?
The client broadcasts another DHCPREQUEST
This allows other DHCPv4 servers to extend the lease.
What is the second step in the lease renewal process after sending a DHCPREQUEST?
DHCP Acknowledgment (DHCPACK)
This message is sent by the server to verify the lease information.
True or False: DHCP messages can only be sent as unicast.
False
DHCP messages can be sent as unicast or broadcast according to IETF RFC 2131.
Fill in the blank: Clients lease the information from the server for an administratively defined _______.
[period]
This period is set by network administrators.
