Users Guide

DHCP server
The Dynamic Host Configuration Protocol (DHCP) server provides network configuration parameters to DHCP clients on
request. A DHCP server dynamically allocates four required IP parameters to each system 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 create and maintain IP address assignments to clients manually.
When you use DHCP to manage a pool of 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.
NOTE: The implementation of DHCP server supports IPv4 and IPv6 addresses.
DHCPv6 server
A Dynamic Host Configuration Protocol version 6 (DHCPv6) server is the IPv6 equivalent of the DHCP server for IPv4. It is used
to automatically allocate IPv6 addresses and distribute network configuration information to IPv6 hosts in a network. You can
configure IPv6 pools with various configurations such as lease time, DNS server, and other user-defined options using DHCPv6.
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 configure an empty DHCP pool under a DHCP pool configuration. For a successful
commit, you must have either a network statement or host/hardware-address (manual binding) configuration. An IP address
pool is a range of addresses that the DHCP server assigns. Both IPv4 and IPv6 DHCP pool configuration is supported. The
subnet number indexes the address pools.
1. Enable the DHCP server in CONFIGURATION 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 specifies
the subnet address. The prefix-length option specifies the number of bits used for the network portion of the address;
for IPv4 addresses, the valid values are from 17 to 30.
network network/prefix-length
4. Enter a range of IP addresses from the subnet specified above, which the DHCP server uses to assign addresses in DHCP
<POOL> mode.
range {ip-address1 [ip-address2]}
NOTE:
Configure at least one interface to match one of the configured network pools. An interface matches a network
pool when its IP address is included in the subnet defined for that network pool. For example, an interface with IP
address 10.1.1.1/24 matches a pool configured 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
System management
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