User`s guide

Configuration through the web interface

DHCP server settings

The DHCP server feature can be enabled in a Digi device to allow other devices or hosts on this

network to be assigned dynamic IP addresses. This DHCP server supports a single subnetwork

scope.

For the DHCP server to operate, the Digi device must be configured to use a static IP address. For

information on how to configure static IP settings, see "Ethernet IP settings" on page 59.

DHCP terminology

Some key DHCP terms involved in configuring a DHCP server include:

scope

A scope is the full consecutive range of possible IP addresses for a network. A scope typically

defines a single physical subnet on your network, to which DHCP services are offered. A scope

is the primary way for the DHCP server to manage distribution and assignment of IP addresses

and related configuration parameters to its clients on the network.

exclusion range

An exclusion range is a limited sequence of IP addresses within a scope, excluded from DHCP

service offerings. Exclusion ranges assure that any addresses in these ranges are not offered by

the server to DHCP clients on your network.

address pool

After the scope is defined and exclusion ranges are applied, the remaining addresses form the

available address pool within the scope. The addresses in this pool are available for dynamic

assignment by the server to DHCP clients on your network.

lease

A lease is the length of time that the DHCP server specifies, during which a client host can use

an assigned IP address. When the DHCP server grants a lease to a client, the lease is active.

Before the lease expires, the client typically needs to renew its address lease assignment with the

DHCP server. A lease becomes inactive when it expires or it is deleted at the server, or if the

client actively releases the lease. The duration of a lease determines when it will expire and how

often the client needs to renew it with the DHCP server in order to retain the lease.

A DHCP server will never grant a lease to its own address. There is no need for its own address

to be in the exclusion range; the DHCP server simply protects its address from being offered.