#DHCPD TFTPSERVER OPTION DOWNLOAD#

Additionally, the FQDN may have been resolved to an IP address and also placed in the 'siaddr' field of the DHCP packet.Ĭarries the filename that is to be downloaded from the server specified in option 66. Note that often the data put into option 66 does not actually appear in the DHCP packet as option 66, but may have been moved into the 'same' field of the DHCP packet.

#DHCPD TFTPSERVER OPTION DOWNLOAD#

For example, the DOCSIS specifications state that if the device is DOCSIS-compliant, option 60 must start with 'DOCSIS' (and also include other details).Ĭarries the FQDN or IP address (or cluster identifier) that the device should use to download the file specified in option 67. The DHCP specification does not define what values go into this field, but other specifications do. This defines the maximum amount of time that the client may use the IP address.Ĭarries some identifier from the client that may identify the client's device class. CableLabs' eDOCSIS specification, for example, defines certain sub-options that appear in this option. Individual vendors can define different pieces of data that may be found in this option. For example, the '' portion of '43Ĭarries some configuration data that is not defined in the standard DHCP RFCs. For example, the '15Ĭarries the domain name portion of a client’s fully qualified domain name (FQDN). This is related to the Time Zone Offset option.Ĭarries the IP address(es) of the DNS servers that the client uses for name resolution.Ĭarries the IP address of the syslog server that receives the client's log messages.Ĭarries the hostname portion of a client’s fully qualified domain name (FQDN). Tells the client the IP address of a time server that can determine the client's current time.

Tells the client which router is the default router. (Eight hours * 60 minutes/hour * 60 seconds/minute) This field would be filled with '- 28800'. For example, Pacific Standard Time is GMT – 8 hours. Informs the client about the time zone offset, in seconds. The subnet mask to apply to the address that is assigned to the client. Please note: Certain classes of devices will use particular subsets, as listed below: The table below describes DHCP options commonly used in IPv4 networks. For further information on other DHCP options, refer to the IETF website. This is because this document aims to act as a guide for the most commonly-used options only. Of course, there will be some DHCPv4, DHCPv6, and internal DHCP options that are not listed at all. However, the administrator can’t configure this option, so therefore it isn’t included in the lists below. For example, DHCPv4 option 53 is the DHCP message type option that declares whether a particular message is a discovery, request, or another message type.

The following tables also do not include options that are only necessary for the operation of the DHCP protocol. Non-configurable options or TLVs have not been included, even though these may be present in a file or on the wire.

The following tables list common, configurable DHCP options.

Dhcpd tftpserver option