Users Guide

DHCP automates network-parameter assignment to network devices. Even in small networks, DHCP makes it easier to add new devices to
the network. The DHCP access service provides a centralized, server-based setup to add clients to the network. This setup means you do
not have to manually create and maintain IP address assignments for clients.
When you use DHCP to manage a pool or IP addresses among hosts, you reduce the number of IP addresses you need. DHCP manages
the IP address pool by leasing an IP address to a host for a limited period, allowing the DHCP server to share a limited number of IP
addresses. DHCP also provides a central database of devices that connects to the network and eliminates duplicate resource assignments.
Automatic address allocation
Automatic address allocation is an address assignment method that the DHCP server uses to lease an IP address to a client from a pool of
available addresses. You cannot congure an empty DHCP pool, under a DHCP pool conguration. For a successful commit, you must have
either a network statement or host/hardware-address (manual binding) conguration. An IP address pool is a range of addresses that the
DHCP server assigns. The subnet number indexes the address pools.
1 Enable DHCP server-assigned dynamic addresses on an interface in DHCP <POOL> mode.
ip dhcp server
2 Create an IP address pool and provide a name in DHCP mode.
pool name
3 Enter the range of IP addresses from which the DHCP server may assign addresses in DHCP<POOL> mode. The network option
species the subnet address. The prefix-length option species the number of bits used for the network portion of the address
(18 to 31).
network network/prefix-length
DHCP server automatic address allocation
OS10(config)# ip dhcp server
OS10(conf-dhcp)# pool Dell
OS10(conf-dhcp-Dell)# network 20.1.1.0/24
Show running conguration
OS10(conf-dhcp-Dell)# do show running-configuration
...
!
ip dhcp server
!
pool Dell
lease 24
network 20.1.1.0/24
default-router 20.1.1.1
Address lease time
Use the lease {days [hours] [minutes] | infinite} command to congure an address lease time (default 24 hours).
OS10(config)# ip dhcp server
OS10(conf-dhcp)# pool Dell
OS10(conf-dhcp-Dell)# lease 36
Default gateway
Ensure the IP address of the default router is on the same subnet as the client.
1 Enable DHCP server-assigned dynamic addresses on an interface in CONFIGURATION mode.
ip dhcp server
System management
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