Example for Configuring a DHCP Server for Clients on the Same Network Segment

This section provides an example for configuring a DHCP server for clients on the same network segment.

Networking Requirements

In a rather large network, if the PCs are connected to the routing device through other devices instead of being directly connected to the routing device through Ethernet interfaces, a network-side DHCPv4 server needs to be configured so that the PCs can dynamically obtain IP addresses from the routing device.

On the network shown in Figure 1, the DHCP server assigns IP addresses to clients on the same network segment. The address pool resides in network segment 10.1.1.0/24 which is divided into two subnets: 10.1.1.0/25 and 10.1.1.128/25. The DHCP server has two GE interfaces whose IP addresses are 10.1.1.1/25 and 10.1.1.129/25, respectively.

The lease of the IP addresses on the network segment 10.1.1.0/25 is 10 days and 12 hours, and the domain name is huawei.com. The DNS server address is 10.1.1.2. There is no NetBIOS address. The gateway address is 10.1.1.1.

The lease of the IP addresses on the network segment 10.1.1.128/25 is 5 days, and the DNS suffix is huawei.com. The DNS server address is 10.1.1.2. The NetBIOS address is 10.1.1.4. The gateway address is 10.1.1.129.

Figure 1 Networking diagram for configuring a DHCP server

Interfaces 1 and 2 in this example represent GE 0/1/0 and GE 0/1/1, respectively.

Configuration Roadmap

The configuration roadmap is as follows:

Configure interface IP addresses.
Configure an address pool.
- Configure a gateway address, an address segment, and the IP addresses that do not take part in automatic assignment (including the DNS server address, NetBIOS server address, and gateway address).
- Configure the NetBIOS server address, DNS server address, and DNS domain name suffix.
- Configure an address lease.

Data Preparation

To complete the configuration, you need the following data:

Interface IP addresses
Gateway address
Address segment number and range
IP addresses prohibited from being assigned
DNS domain name suffix and DNS server address
Address lease

Procedure

Configure IP addresses for the interfaces on the DHCP server and enable the DHCP server function on them.

<HUAWEI> system-view
[~HUAWEI] interface gigabitethernet 0/1/0
[~HUAWEI-GigabitEthernet0/1/0] ip address 10.1.1.1 255.255.255.128
[~HUAWEI-GigabitEthernet0/1/0] dhcp server enable
[*HUAWEI-GigabitEthernet0/1/0] undo shutdown
[*HUAWEI-GigabitEthernet0/1/0] quit
[*HUAWEI] interface gigabitethernet 0/1/1
[*HUAWEI-GigabitEthernet0/1/1] ip address 10.1.1.129 255.255.255.128
[*HUAWEI-GigabitEthernet0/1/1] dhcp server enable
[*HUAWEI-GigabitEthernet0/1/1] undo shutdown
[*HUAWEI-GigabitEthernet0/1/1] quit
[*HUAWEI] commit

Configure address pool 1 on the DHCP server.

# Configure a gateway address, an address segment, and the IP address that do not take part in automatic assignment.

[~HUAWEI] dhcp enable
[*HUAWEI] ip pool pool1 server
[*HUAWEI-ip-pool-pool1] gateway 10.1.1.1 255.255.255.128
[*HUAWEI-ip-pool-pool1] section 0 10.1.1.2 10.1.1.126
[*HUAWEI-ip-pool-pool1] excluded-ip-address 10.1.1.2
[*HUAWEI-ip-pool-pool1] excluded-ip-address 10.1.1.4

# Configure the DNS server address and DNS domain name suffix.

[*HUAWEI-ip-pool-pool1] dns-server 10.1.1.2
[*HUAWEI-ip-pool-pool1] dns-suffix huawei.com

# Configure an address lease.

[*HUAWEI-ip-pool-pool1] lease 10 12
[*HUAWEI-ip-pool-pool1] quit
[*HUAWEI] commit

Configure address pool 2 on the DHCP server.

# Configure a gateway address and an address segment.

[~HUAWEI] ip pool pool2 server
[*HUAWEI-ip-pool-pool2] gateway 10.1.1.129 255.255.255.128
[*HUAWEI-ip-pool-pool2] section 0 10.1.1.130 10.1.1.254

# Configure the NetBIOS server address, DNS server address, and DNS domain name suffix.

[*HUAWEI-ip-pool-pool2] netbios-name-server 10.1.1.4
[*HUAWEI-ip-pool-pool2] dns-server 10.1.1.2
[*HUAWEI-ip-pool-pool2] dns-suffix huawei.com

# Configure an address lease.

[*HUAWEI-ip-pool-pool2] lease 5
[*HUAWEI-ip-pool-pool2] quit
[*HUAWEI] commit

Verify the configuration.

# Run the display ip pool command on the DHCP server to check the IP address pool configuration.

[~HUAWEI] display ip pool name pool1
Pool-Name      : pool1
  Pool-No        : 1
  Pool-constant-index: -
  Lease          : 10 Days 12 Hours 0 Minutes
  NetBios Type   : N-Node
  Auto recycle   : 30
  Option 3       : Enable
  DNS-Suffix     : huawei.com
  Dom-Search-List0: -
  Dom-Search-List1: - 
  Dom-Search-List2: -
  Dom-Search-List3: -
  Option-Code 125 : enterprise-code : 2011, string: -
  DNS1         :10.1.1.2
  Position       : Server          Status           : Unlocked        
  RUI-Flag       : -
  Attribute      : Private         
  Gateway        : 10.1.1.1        Mask             : 255.255.255.128   
  Vpn instance   : --              Unnumbered gateway: -               
  Profile-Name   : -               Server-Name     : -               
  Total Idle     : 123             Have Dhcp IP     : 1
  Timeouts       : 0
  Timeout Count  : 0               Sub Option Count : 0               
  Option Count   : 0               Force-reply Count: 0               
  Codes: CFLCT(conflicted)
  ---------------------------------------------------------------------------------------
  ID           start             end total  used  idle CFLCT disable reserved static-bind
  ---------------------------------------------------------------------------------------
   0        10.1.1.2      10.1.1.126   125     0   123     0       2        0           0
  ---------------------------------------------------------------------------------------
[~HUAWEI] display ip pool name pool2
Pool-Name      : pool2
  Pool-No        : 2
  Pool-constant-index: -
  Lease          : 5 Days 0 Hours 0 Minutes
  NetBios Type   : N-Node
  Auto recycle   : 30
  Option 3       : Enable
  DNS-Suffix     : huawei.com
  Dom-Search-List0: -
  Dom-Search-List1: - 
  Dom-Search-List2: -
  Dom-Search-List3: -
  Option-Code 125 : enterprise-code : 2011, string: -
  DNS1         :10.1.1.2
  Position       : Server          Status           : Unlocked        
  RUI-Flag       : -
  Attribute      : Private         
  Gateway        : 10.1.1.129      Mask             : 255.255.255.128   
  Vpn instance   : --              Unnumbered gateway: -               
  Profile-Name   : -               Server-Name     : -               
  Total Idle     : 125             Have Dhcp IP     : 1
  Timeouts       : 0
  Timeout Count  : 0               Sub Option Count : 0               
  Option Count   : 0               Force-reply Count: 0               
  Codes: CFLCT(conflicted)
  ---------------------------------------------------------------------------------------
  ID           start             end total  used  idle CFLCT disable reserved static-bind
  ---------------------------------------------------------------------------------------
   0      10.1.1.130      10.1.1.254   125     0   125     0       0        0           0
  ---------------------------------------------------------------------------------------

Configuration File

DHCP server configuration file

#
dhcp enable
#
interface GigabitEthernet0/1/0
 undo shutdown
 ip address 10.1.1.1 255.255.255.128
 dhcp server enable
#
interface GigabitEthernet0/1/1
 undo shutdown
 ip address 10.1.1.129 255.255.255.128
 dhcp server enable
#
ip pool pool1 server
 gateway 10.1.1.1 255.255.255.128
 section 0 10.1.1.2 10.1.1.126
 excluded-ip-address 10.1.1.2
 excluded-ip-address 10.1.1.4
 dns-server 10.1.1.2
 dns-suffix huawei.com
 lease 10 12
#
ip pool pool2 server
 gateway 10.1.1.129 255.255.255.128
 section 0 10.1.1.130 10.1.1.254
 dns-server 10.1.1.2
 dns-suffix huawei.com
 netbios-name-server 10.1.1.4
 lease 5
#
return