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 Enter the starting IP

address

for the DHCP

server’s IP

 

Address

 

assignment and the

ending

IP address for

the DHCP

 

 

server’s IP assignment.

 

 

 

 

 

 

 

 

 

 

 

 

DHCP IPLease

Assign the length of time for the IP lease, default setting is

 

Time

 

86400 seconds.

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 4-4. DHCP server description

 

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