Dell EMC SmartFabric OS10 User Guide Release 10.5.2

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. For the DHCP server to process DHCP discovery packets, you must configure the IP address pool that matches the interfaces where packets are received. This configuration applies even though the leased IP addresses are meant for a totally different subnet.

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 configuration

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

OS10(config)# ip dhcp server
OS10(conf-dhcp)# pool Dell
OS10(conf-dhcp-Dell)# lease 36

OS10(config)# ip dhcp server
OS10(conf-dhcp)# pool Dell
OS10(conf-dhcp-Dell)# default-router 20.1.1.1

OS10(config)# ip dhcp server
OS10(conf-dhcp)# no disable