John Hascall john at
Tue Jun 5 13:44:01 UTC 2007

> I'm trying to specify dhcp option 43 in order for my access points to
> be able to find in the DHCP server their own ip pools, coz i want DHCP
> to recognize which AP is requesting ip and depend of the AP is the pool
> of ips im goona use. I'm just wondering how I specify this in the
> dhcp.conf file? Im using DHCP 3.03 and Linksys wap54g.
> Any help is appreciated.

The content of option 43 is specific to the end device using it
-- in your case your wap54g's documentation should cover what
goes in option 43.   You specify the option itself like any other:

Here is a basic example from my dhcpd.conf file:

	# here I give it the very creative name "option-43"
	option option-43  code  43 = text;
	# then later it gets used:
	host {
	#  ...other stuff...
		option option-43 ",";

As you can see, this device is expecting option 43 to be a text string.
Often, though, option 43 is used to pass a group of options to the
end device and when this is the case they are often encode in a
type-length-data format -- like this for example:

  option option-43 06:01:07:08:07:00:de:ad:be:ef:ca:fe;

here there are two type-length-data suboptions in it:

  06:01:07                     suboption #6, length 1, data 7
  08:07:00:de:ad:be:ef:ca:fe   suboption #8, length 7, data 00:de:ad:be:ef:ca:fe

sometimes there is a special flag byte (like "ff") to mark the end of the data.

  option option-43 06:01:07:08:07:00:de:ad:be:ef:ca:fe:ff;
Hope this is some help.


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