Expired Time of the DHCP lease for each client computer. DHCP Server is a useful tool that automates
the assignment of IP addresses to numbers of computers in your network. The server maintains a pool
of IP addresses that you use to create scopes. (A DHCP scope is a collection of IP addresses and
TCP/IP configuration parameters that are available for DHCP clients to lease.) Then, the server
automatically allocates these IP addresses and related TCP/IP configuration settings to DHCP-enabled
clients in the network. The DHCP Server leases the IP addresses to clients for a period that you specify
when you create a scope. A lease becomes inactive when it expires. Through the DHCP Server, you
can reserve specific IP addresses permanently for hardware devices that must have a static IP address
(e.g., a DNS Server).
An advantage of using DHCP is that the service assigns addresses dynamically. The DHCP Server
returns addresses that are no longer in use to the IP addresses pool so that the server can reallocate
them to other machines in the network. If you disable this DHCP, you would have to manually configure
IP for new computers, keep track of IP addresses so that you could reassign addresses that clients
aren't using, and reconfigure computers that you move from one subnet to another. The DHCP Static
MAP table lists all MAC and IP address which are active now.
Figure 4-11. DHCP server settings
When you enable the DHCP server, you are able to enter:
Assigned DHCP IP
Address
Enter the starting IP address for the DHCP server’s IP
assignment and the ending IP address for the DHCP
server’s IP assignment.
DHCP IP Lease
Time
Assign the length of time for the IP lease, default setting is
86400 seconds.
Table 4-4. DHCP server description
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