Connectivity Guide

DHCP server
The Dynamic Host Conguration Protocol (DHCP) server provides network conguration parameters to DHCP clients on request. A DHCP
server dynamically allocates four required IP parameters to each computer on the virtual local area network (VLAN) — the IP address,
network mask, default gateway, and name server address. DHCP IP address allocation works on a client/server model where the server
assigns the client reusable IP information from an address pool.
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 subnet 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
4 Enter a range of IP addresses from the subnet specied above, which the DHCP server uses to assign addresses in DHCP <POOL>
mode.
range {ip-address1 [ip-address2]}
NOTE
: NOTE: Congure at least one interface to match one of the congured network pools. An interface matches a
network pool when its IP address is included in the subnet dened for that network pool. For example, an interface
with IP address 10.1.1.1/24 matches a pool congured with network 10.1.1.0/24.
DHCP server automatic address allocation
OS10(config)# ip dhcp server
OS10(config-dhcp)# pool Dell
OS10(config-dhcp-Dell)# default-router 20.1.1.1
OS10(config-dhcp-Dell)# network 20.1.1.0/24
OS10(config-dhcp-Dell)# range 20.1.1.2 20.1.1.8
Show running conguration
OS10(conf-dhcp-Dell)# do show running-configuration
...
!
ip dhcp server
!
pool Dell
network 20.1.1.0/24
default-router 20.1.1.1
range 20.1.1.2 20.1.1.8
584
System management