m (Shin moved page DHCP Server option configuration to DHCP Option configuration) |
Revision as of 11:35, 15 April 2021
DHCP > DHCP Option
A DHCP server can provide optional configuration parameters to the client. The Dynamic Host Configuration Protocol(DHCP) provides a framework for passing configuration information to hosts. Configuration parameters and other control information are carried in tagged data items that are stored in the 'options' field of the DHCP message. The data items themselves are also called "options."
The IP address is also one of the DHCP options and is supplied from a DHCP pool. But other options(e.g. "Domain Name Server", "NTP", and so on) should be configured.
The imRAD has many DHCP options that have been defined by the Internet Assigned Numbers Authority (IANA).[1][2] If no DHCP option exists, you can define a new DHCP option from the DHCP Option Definition.
DHCP Option Configuration
You can configure the values in which one of the predefined DHCP options. It opens an interface(Figure-1) that can configure a DHCP option from the "Configure DHCP Option" button at the right top of the DHCP > DHCP Option or from the dropdown menu of the DHCP pool list.
You can add several values in a DHCP option in the interface(Figure-1). By dragging the icon(
) in front of each value allows you can change the order of values. This order is sensitive for some DHCP options.
For example, If there are two Domain Name System (DNS) addresses, the first one is provided as the Primary DNS, and the second one is the Secondary DNS.
If you hover the mouse on a configured value, it shows a trash icon behind the list. By clicking the trash icon, you can delete a value of a DHCP option.
If you want to modify a configured value, you have to delete it and add a new value.
| Item | Description |
|---|---|
| DHCP Version | It is the DHCP version. Choose either DHCPv4 or DHCPv6. |
| [Code] Name | It is the name of the DHCP option. The code is the value that is specified to a DHCP option[3]. |
| Data type | It is the data type of the DHCP Option. There are several data types and |
| Target DHCP Pool | You can globally or exclusively for a specific DHCP pool define the value of a DHCP option. |
| Data Value | It is the value of the DHCP option, For example, if the DHCP option is the Domain Name System(6), you may input a value as "8.8.8.8". |
If a DHCP option is exclusively for a specific DHCP pool, the option will be provided only to clients that request IP addresses in the specific DHCP pool.
After configuring a new value of a DHCP option from the DHCP Option menu, It shows the DHCP option like in Figure-2.
Figure-2
DHCP Option Definition
If no DHCP option exists, you can define a new DHCP option by clicking the "Define DHCP Option" button at the top right in the DHCP Option menu. If you want to modify something of the predefined DHCP options, you can also do it from this.
New DHCP Option
| Item | Required | Description |
|---|---|---|
| DHCP Version | Yes | DHCPv4 or DHCPv6 |
| Code | Yes | Input the code of a new DHCP option. the code must be numeric. |
| Name | Yes | It is the name of a new DHCP option. |
| Description | No | It is the description of a new DHCP option. |
| Data type | Yes | Choose one of them. |
Predefined DHCP Option
DHCP 서버 옵션에 데이터가 이미 설정된 경우 삭제를 할 수 없습니다.
| 이름 | 필수 | 설명 |
|---|---|---|
| DHCP 버전 | 예 | 변경 불가 |
| 코드 | 예 | 변경 불가 |
| 이름 | 예 | DHCP 서버 옵션 이름 |
| 설명 | 아니오 | DHCP 서버 옵션 설명 |
| 유형 | 예 | DHCP 서버 옵션 유형 중 하나를 선택, 단, 이미 데이터가 있는 경우 유형 변경 불가 |
DHCP Option Data Types
| 이름 | 설명 |
|---|---|
| IPv4 | IPv4 Address |
| IPv6 | IPv6 Address |
| LONG | 4 바이트 정수 |
| SHORT | 2 바이트 정수 |
| BYTE | 1 바이트 정수 |
| TEXT | 문자 |
| MIX | 여러 가지 형식 |