DHCP Server

You can configure the Gaia device to be a Dynamic Host Configuration Protocol (DHCP) server. The DHCP server gives IP addresses and other network parameters to network hosts. DHCP makes it unnecessary to configure each host manually, and therefore reduces configuration errors.

You configure DHCP server subnets on the Gaia device interfaces. A DHCP subnet allocates these network parameters to hosts behind the Gaia interface:

IPv4 address
Default Gateway (optional)
DNS parameters (optional):
- Domain name
- Primary, secondary and tertiary DNS servers

This is the general workflow for allocating DHCP parameters to hosts (for the details, see the next section):

Step	Description
1	To define a DHCP subnet on a Gaia interface: Enable DHCP Server on the Gaia network interface. Define the network IPv4 address of the subnet on the interface. Define an IPv4 address pool. Optional: Define routing and DNS parameters for DHCP hosts.
2	Define additional DHCP subnets on other Gaia interfaces, as needed.
3	Enable the DHCP Server process for all configured subnets.
4	Configure the network hosts to use the Gaia DHCP server.

Configuring a DHCP Server - Gaia Portal

To allocate DHCP parameters to hosts:

Step	Description
1	In the navigation tree, click Network Management > DHCP Server.
2	In the DHCP Server Subnet Configuration section, click Add. The Add DHCP window opens. You now define a DHCP subnet on an Ethernet interface of the Gaia device. Hosts behind the Gaia interface get IPv4 addresses from address pools in the subnet.
3	Select Enable DHCP to enable DHCP for the subnet you will configure.
4	On the Subnet tab: Define the DHCP offer and lease settings:
4A	In the Network IP Address field, enter the IPv4 address of the applicable interface's subnet. In the Subnet mask field, enter the subnet mask. Note - To do this automatically, click Get from interface, select the applicable interface and click OK.
4B	In the Address Pool section, click Add to define the range of IPv4 addresses that the server assigns to hosts. In the Type field, select Include or Exclude. This specifies whether to include or exclude this range of IPv4 addresses in the IP pool. In the Status field, select Enable of Disable. This enables or disables the DHCP Server for this subnet, or the DHCP Server process (depending on the context). In the Start field, enter the first IPv4 address of the range. In the End field, enter the last IPv4 address of the range. Click OK.
4C	In the Lease Configuration section, configure the DHCP lease settings: Optional: In the Default lease field, enter the default lease time (in seconds), for host IPv4 addresses. This applies only if DHCP clients do not request a unique lease time. The default is 43,200 seconds. Optional: In the Maximum Lease field, enter the maximal lease time (in seconds), for host IPv4 addresses. The default is 86,400 seconds.
5	Optional: On the Routing & DNS tab: Define routing and DNS parameters for DHCP clients: In the Default Gateway field, enter the IPv4 address of the default gateway for the DHCP clients. In the Domain Name field, enter the domain name for the DHCP clients (for example, `example.com`). In the Primary DNS Server field, enter the IPv4 address of the Primary DNS server for the DHCP clients. In the Secondary DNS Server field, enter the IPv4 address of the Secondary DNS server for the DHCP clients (to use if the primary DNS server does not respond). In the Tertiary DNS Server field, enter the IPv4 address of the Tertiary DNS server for the DHCP clients (to use if the primary and secondary DNS servers do not respond).
6	Click OK.
7	Optional: Define DHCP subnets on other Gaia interfaces, as needed.
8	In the DHCP Server Configuration section, select Enable DHCP Server and click Apply.

The DHCP server on Gaia is now configured and enabled.

You can now configure your network hosts to get their network parameters from the DHCP server on Gaia.

To change DHCP parameters in a subnet:

Step	Description
1	In the navigation tree, click Network Management > DHCP Server.
2	In the DHCP Server Subnet Configuration section, select the Subnet and click Edit.
3	Change the applicable settings.
4	Click OK.

To disable DHCP server on all interfaces:

Step	Description
1	In the navigation tree, click Network Management > DHCP Server.
2	In the DHCP Server Configuration section, clear the Enable DHCP Server.
3	Click Apply.

To delete DHCP subnet:

Step	Description
1	In the navigation tree, click Network Management > DHCP Server.
2	In the DHCP Server Subnet Configuration section, select the Subnet and click Delete.
3	Click OK to confirm.

Note - Before deleting the last DHCP subnet, you must disable DHCP server on all interfaces.

Configuring a DHCP Server - Gaia Clish

Description

Configure the Gaia device as DHCP Server for your network hosts.

Syntax

To add a DHCP Server subnet:

add dhcp server subnet <Subnet Entry>

netmask <Mask>

include-ip-pool start <First IPv4 Address> end <Last IPv4 Address>

exclude-ip-pool start <First IPv4 Address> end <Last IPv4 Address>

To configure a DHCP Server subnet:

set dhcp server subnet <Subnet Entry>

enable

disable

include-ip-pool <First IPv4 Address-Last IPv4 Address> {enable | disable}

exclude-ip-pool <First IPv4 Address-Last IPv4 Address> {enable | disable}

default-lease <Lease in Seconds>

max-lease <Maximal Lease in Seconds>

default-gateway <Gateway IPv4 Address>

domain <Domain Name for the DHCP Clients>

dns <DNS Server IPv4 Address>

To delete a DHCP Server subnet:

delete dhcp server subnet <Subnet Entry>

include-ip-pool <First IPv4 Address-Last IPv4 Address>

exclude-ip-pool <First IPv4 Address-Last IPv4 Address>
To enable or disable the DHCP Server process:

set dhcp server {enable | disable}
To show DHCP Server configuration:

show dhcp server

all

status

subnet <Subnet Entry> ip-pools

subnets

Important - After you add, configure, or delete features, run the save config command to save the settings permanently.

Parameters

Parameter	Description
`subnet` <Subnet Entry>	Specifies the IPv4 address of the DHCP subnet on an Ethernet interface of the Gaia device. Hosts behind the Gaia interface get IPv4 addresses from address pools in the subnet. For example: `192.0.2.0`
`netmask` <Mask>	Specifies the IPv4 subnet mask in CIDR notation. For example: `24`
`include-ip-pool start` <First IPv4 Address> `end` <Last IPv4 Address>	Specifies the IPv4 address that starts and the IPv4 address that ends the included allocated IP Pool range. For example: `192.0.2.20` and `192.0.2.90`
`exclude-ip-pool start` <First IPv4 Address> `end` <Last IPv4 Address>	Specifies the IPv4 address that starts and the IPv4 address that ends the excluded allocated IP Pool range. For example: `192.0.2.155` and `192.0.2.254`
`include-ip-pool` <First IPv4 Address-Last IPv4 Address>	Specifies the range of IPv4 addresses to include in the IP pool. For example: `192.0.2.20-192.0.2.90`
`exclude-ip-pool` <First IPv4 Address-Last IPv4 Address>	Specifies the range of IPv4 addresses to exclude from the IP pool. For example: `192.0.2.155-192.0.2.254`
`enable`	Enables the DHCP Server subnet, or the DHCP Server process (depending on the context).
`disable`	Disables the DHCP Server subnet, or the DHCP Server process (depending on the context).
`default-lease` <Lease in Seconds>	Specifies the default DHCP lease in seconds, for host IPv4 addresses. Applies only if DHCP clients do not request a unique lease time. If you do not enter a value, the default is 43,200 seconds.
`max-lease` <Maximal Lease in Seconds>	Specifies the maximal DHCP lease in seconds, for host IPv4 addresses. This is the longest lease available. If you do not enter a value, the configuration default is 86,400 seconds.
`default-gateway` <Gateway IPv4 Address>	Optional. Specifies the IPv4 address of the default gateway for the network hosts
`domain` <Domain Name for the DHCP Clients>	Optional. Specifies the domain name of the network hosts. For example: `example.com`
`dns` <DNS Server IPv4 Address>	Optional. Specifies the DNS servers that the network hosts will use to resolve hostnames. Optionally, specify a primary, secondary and tertiary server in the order of precedence. For example: `192.0.2.101, 192.0.2.102, 192.0.2.103`
`all`	Shows all DHCP Server's configuration settings.
`subnets`	Configures the DHCP Server subnet settings.
`subnet` <Subnet Entry> `ip-pools`	The IP addresses pools in the DHCP Server subnet, and their status: Enabled or Disabled.
`status`	The status of the DHCP Server process: Enabled or Disabled.

Example

gaia> add dhcp server subnet 192.168.2.0 netmask 24

gaia> add dhcp server subnet 192.168.2.0 include-ip-pool start 192.168.2.20 end 192.168.2.90

gaia> add dhcp server subnet 192.168.2.0 include-ip-pool start 192.168.2.120 end 192.168.2.150

gaia> add dhcp server subnet 192.168.2.0 exclude-ip-pool start 192.168.2.155 end 192.168.2.254

gaia> set dhcp server subnet 192.168.2.0 include-ip-pool 192.168.2.20-192.168.2.90 enable

gaia> set dhcp server subnet 192.168.2.0 include-ip-pool 192.168.2.120-192.168.2.150 disable

gaia> set dhcp server subnet 192.168.2.0 exclude-ip-pool 192.168.2.155-192.168.2.254 enable

gaia> set dhcp server subnet 192.168.2.0 default-lease 43200

gaia> set dhcp server subnet 192.168.2.0 max-lease 86400

gaia> set dhcp server subnet 192.168.2.0 default-gateway 192.168.2.103

gaia> set dhcp server subnet 192.168.2.0 domain example.com

gaia> set dhcp server subnet 192.168.2.0 dns 192.168.2.101, 192.168.2.102, 192.168.2.103

gaia> set dhcp server subnet 192.168.2.0 enable

gaia> add dhcp server subnet 172.30.4.0 netmask 24

gaia> add dhcp server subnet 172.30.4.0 include-ip-pool start 172.30.4.10 end 172.30.4.99

gaia> set dhcp server subnet 172.30.4.0 include-ip-pool 172.30.4.10-172.30.4.99 enable

gaia> set dhcp server subnet 172.30.4.0 default-lease 43200

gaia> set dhcp server subnet 172.30.4.0 max-lease 86400

gaia> set dhcp server subnet 172.30.4.0 disable

gaia> add dhcp server subnet 10.20.30.0 netmask 24

gaia> set dhcp server subnet 10.20.30.0 default-lease 43200

gaia> set dhcp server subnet 10.20.30.0 max-lease 86400

gaia> set dhcp server subnet 10.20.30.0 disable

gaia> show dhcp server all

DHCP Server Enabled

DHCP-Subnet 192.168.2.0

State Enabled

Net-Mask 24

Maximum-Lease 86400

Default-Lease 43200

Domain example.com

Default Gateway 192.168.2.103

DNS 192.168.2.101, 192.168.2.102, 192.168.2.103

Pools (Include List)

192.168.2.20-192.168.2.90 : enabled

192.168.2.120-192.168.2.150 : disabled

Pools (Exclude List)

192.168.2.155-192.168.2.254 : enabled

DHCP-Subnet 172.30.4.0

State Disabled

Net-Mask 24

Maximum-Lease 86400

Default-Lease 43200

Pools (Include List)

172.30.4.10-172.30.4.99 : enabled

DHCP-Subnet 10.20.30.0

State Disabled

Net-Mask 24

Maximum-Lease 86400

Default-Lease 43200

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