Download Digi ConnectPort X4 User`s guide

Configuration through the web interface
DHCP server configuration settings
Here are the configuration settings for the DHCP server. Typically, these settings can be modified
without having to restart the DHCP server for the changes to become effective in the running
server.

Enable Dynamic Host Configuration Protocol (DHCP) Server: Enables the DHCP
server feature on this Digi device. Note that 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 55.
–
Scope Name: The name of the physical network interface associated with the subnet
being served by the DHCP Server. Most Digi device models have a single network
interface, so there is no choice for the scope name. For models that have multiple
network interfaces, such as an Ethernet interface and a Wi-Fi (802.11) interface, this
DHCP Server may be configured to provide services on either of those interfaces.
–
IP Addresses: The starting and ending IP addresses for the scope being served by this
DHCP server. These addresses must be in the same subnet as the Digi device itself.
–
Lease Duration: The length of the leases for the scope being served by this DHCP
server. The default lease duration is 24 hours. A DHCP client may request a lease
duration other than this setting, and the DHCP server will grant that request if possible.

Wait specified delay before sending DHCP offer reply: The interval of time in
milliseconds to delay before offering a lease to a new client. The default delay is 500ms,
and the range is 0 to 5000ms. Use of this delay permits this Digi device to reside on a
network with other DHCP servers, yet not offer leases to new clients unless the other
DHCP servers do not make such an offer. This provides a measure of protection against
inadvertently connecting a Digi device to a network that is running its own DHCP
server(s), and offering leases to clients in a manner inconsistent with that network.

Check that an IP address is not in use before offering it: When a DHCP client
requests a new IP address lease, before offering an IP address to that client, use “ping”
to test whether that IP address is already in use by another host on the network but is
unknown to the DHCP server. If an IP address is determined to be in use, it is marked as
Unavailable for a period of time, and it will not be offered to any client while in this
state. Enabling this test adds approximately one second of delay before the IP address is
offered to the client, since the “ping” test must not receive a valid reply for that test to
successfully determine that the IP address is not already in use. This option is off
(disabled) by default. This option does not apply to Static Lease Reservations, since the
“ping” test is not used for them.
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