Work Out the DHCP Scope and Lease

About this interactive

From the lesson: - **Counting a scope:** from .15 to .240 is 240 - 15 + 1 = 226 addresses. Count both ends. - **Two servers, two scopes:** split the range so they never overlap (.15 to .130 and .131 to .240), or both could hand out .45 to two machines. - **Renewing:** a client asks to renew halfway through its lease: every 12 hours on a 1-day lease. - **Long or short leases:** long leases mean less renewal traffic; short ones free addresses faster where devices come and go. - **Seconds:** a config file sets leases in seconds. 12 hours is 12 × 60 × 60 = 43,200. In the demo the first figure typed for 12 hours, 8,640, is wrong; it is then corrected to 43,200. - **No server at all:** the client gives itself a link-local (APIPA) address, 169.254.x.x.

What you'll learn

Count the addresses in a DHCP scope, and in two non-overlapping scopes split between two servers
Work out when a client first renews (halfway through its lease), and convert lease times between days, hours, minutes and seconds

Aligned to

CompTIA Network+

3.4 Given a scenario, implement IPv4 and IPv6 network services.

Cisco CCNA

4.3 Explain the role of DHCP and DNS within the network

Key terms

DHCP Scope: The defined pool of IP addresses that a DHCP server is configured to assign to clients on a specific subnet, along with associated options such as the subnet mask, default gateway, and DNS servers. Each subnet served by a DHCP server has its own scope.
DHCP Lease Time: The duration for which a DHCP server assigns an IP address to a client before the address must be renewed or released.
DHCP Exclusion Range: A configured range of IP addresses within a DHCP pool that the server will not assign dynamically, reserving them for static assignment to specific devices.
DHCP Lease: The amount of time a client is permitted to use an IP address assigned by a DHCP server before it must be renewed or released.

Topics

Dhcp Dhcp Scope Dhcp Lease Interactive Calculation

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