DHCP Flashcards
IP range
The range of IP addresses that the DHCP server can assign.
Subnet mask
The structure of an IP address that defines the network ID and host ID.
Exclusions
IP addresses that the DHCP server will not assign.
Reservations
Static IP addresses that are not dynamically assigned by the DHCP server.
DHCP lease time
The specified amount of time that an IP configuration assigned by DHCP is valid. It is specified when a device is assigned an IP configuration.
Default gateway
The gateway where data packets that are leaving the network should go to be routed.
static IP
IP address that has been manually configured. This means the address will not change even if the device disconnects from the network.
dynamic IP
IP address that is automatically assigned. The IP configuration is handled by the Dynamic Host Configuration Protocol (DHCP).
IP range
The IP range defines the range of IP addresses that the DHCP server can assign. When a new device connects to the network, the DHCP server assigns the next available address.
When defining the IP range:
All available addresses in the network can be assigned.
Only specific ranges can be assigned (e.g., 192.168.5.50 - 192.168.5.100).
Specifying a limited number of addresses can help limit the number of connections to the network.
Subnet mask
The subnet mask defines the network ID and host ID. The subnet mask must be defined.
Exclusions
Exclusions are IP addresses that the DHCP server will not assign. Be aware that exclusion addresses:
Are typically used for devices such as servers, printers, routers, or other network devices that must have a static IP address.
Must be manually configured on each device. It’s important to remember that the exclusion addresses must fall within the configured IP range of the scope.
Reservations
Reservations are static IP addresses that are not dynamically assigned by the DHCP server.
Reservations are assigned by the DHCP server using the device’s MAC address.
Whenever the device with the specified MAC address connects to the network, the DHCP server assigns it the reserved static IP configuration.
DHCP lease time
When a device is assigned an IP configuration, it is for a specified amount of time. This is the DHCP lease.
While a lease is active, that IP address cannot be reassigned, even if the device disconnects from the network.
When the lease is half over, a device still connected to the network will attempt to renew the lease.
A lease can be set for a few hours up to many days, weeks, or months.
If the device stays connected to the network, set the lease to last for days.
If clients are connecting for only a short period of time (e.g., a guest network), set the lease accordingly so available addresses aren’t tied up.
Default gateway
The default gateway defines where data packets that are leaving the network should go. An example is packet going to the internet are sent to the default gateway.
DNS server
If a specific DNS server is being used, define it in the scope.
