Multiple subnets on one Interface

[Steve Clark]

On 01/28/2014 01:19 AM, Glenn Satchell wrote:
> On Tue, January 28, 2014 9:15 am, Simon Hobson wrote:
>> Steve Clark <sclark at netwolves.com> wrote:
>>
>>> How will dhcpd give out ips? Will it alternate? Give all of one subnet
>>> then start the other
>>> subnet?
>> The official answer is that it is not determinate - as in you cannot in
>> any way rely on any specific allocation order.
>>
>> The practical answer is that *currently* the implementation dependent
>> order is that it will allocate unused addresses starting with the
>> numerically highest and working down - I believe this is due to the way
>> the internal hashing tables work. This is implementation dependent, not
>> officially documented, and liable to change at any time without warning -
>> if you want a specific allocation strategy then you will need to
>> explicitly define it in the config.
> Further, it doesn't really matter, as once it gets to steady-state it will
> be issuing IPs on a least recently used basis, so will essentially be
> random. Exactly the same way it is with a single subnet.
>
> A common desire it to use fixed-address devices in one of the subnets, and
> a dynamic range in the other. Another option is to use a class to select
> some subset of devices and then use a pool in each subnet, one allowing
> the class and the other denying the class.
>
> regards,
> -glenn
>
>
Thanks to all that answered.

I just wanted to make sure that when all the ips from one subnet were handed out
then dhcpd would start handing out ips from the next subnet.

Steve


-- 
Stephen Clark
*NetWolves*
Director of Technology
Phone: 813-579-3200
Fax: 813-882-0209
Email: steve.clark at netwolves.com
http://www.netwolves.com
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