how define network with mask 8 for dhcp server?

[s m]

thanks Andreas, that's it!!!
you know i have user interface program for dhcp. users don't know how dhcp
works and just enter desired range in text box. i should handle all entered
ranges. in order to do that, i should know how dhcp works with all
different ranges and return errors if some ranges is not equivalent like
the sample one.

so. if i want to have network with mask 8, i should limit my range, right?
have you any suggestion what is the maximum range for netmask 8?
thanks for your reply again. it clears my mind:)


On Tue, Aug 6, 2013 at 1:35 PM, Andreas Nilsson <andrnils at gmail.com> wrote:

>
>
>
> On Tue, Aug 6, 2013 at 10:59 AM, Andreas Nilsson <andrnils at gmail.com>wrote:
>
>>
>>
>>
>> On Tue, Aug 6, 2013 at 10:40 AM, Olivier Nicole <
>> olivier.nicole at cs.ait.ac.th> wrote:
>>
>>> Sam,
>>>
>>> > my problem is to know how define a network with mask 8 and dhcp server
>>> > works correctly with it! you know if i config my dhcpd.conf like
>>> below, i
>>> > have core dump either:
>>> > subnet 10.0.0.0 netmask 255.0.0.0
>>> > {
>>> >     range 10.0.0.1 10.255.255.254;
>>> > }
>>> >
>>> > do you know how should i define my range ??
>>>
>>> The reason may be that 2^24 machines in a subnet is such a non-sense
>>> that dhcp simply cannot manage it.
>>>
>>> Best regards,
>>>
>>> Olivier
>>>
>>> >
>>> > On Tue, Aug 6, 2013 at 12:23 PM, Olivier Nicole <
>>> Olivier.Nicole at cs.ait.ac.th
>>> >> wrote:
>>> >
>>> >> Sam,
>>> >>
>>> >> > subnet 192.0.0.0 netmask 255.0.0.0
>>> >>
>>> >> I know it is not the answer to your question, but you are wrong in
>>> your
>>> >> guess that 192.0.0.0/8 is all private IPs. Only 192.168.0.0/16 is.
>>> >>
>>> >> I know that for certain because my own IP starts with 192.
>>> >>
>>> >> If you want a full /8 private, you can only use 10.0.0.0/8
>>> >>
>>> >> Bets regards,
>>> >>
>>> >> Olivier
>>> >>
>>> >> --
>>> >>
>>>
>>>
>> Well, I would guess it may run out of memory... I did a few tests:
>> 192.0.0.0 - 192.128.255.255 does work ( using ~2.5Gb  RAM ).
>> 192.0.0.0 - 192.192.255.255 does work ( using ~4Gb RAM ).
>> 192.0.0.0 - 192.200.255.255 does work ( using ~4.2Gb RAM ).
>> 192.0.0.0 - 192.224.255.255 dumps core
>>
>> Why would you want to have such a huge range?
>>
>> Best regards
>> Andreas
>>
>
> Also, a quick look at the core file gives same indications:
> #0  0x0000000800c67a21 in _malloc_prefork () from /lib/libc.so.7
> #1  0x0000000800c6b72a in malloc () from /lib/libc.so.7
> #2  0x000000000047b43b in omapi_object_dereference ()
> #3  0x00000000004844db in do_ip4_hash ()
> #4  0x0000000000484571 in do_ip4_hash ()
> #5  0x0000000000438a45 in pool_timer ()
> #6  0x000000000041dcd7 in trace_conf_stop ()
> #7  0x000000000041fc4e in trace_conf_stop ()
> #8  0x0000000000420698 in trace_conf_stop ()
> #9  0x0000000000420ecc in trace_conf_stop ()
> #10 0x0000000000420197 in trace_conf_stop ()
> #11 0x00000000004247f3 in trace_conf_stop ()
> #12 0x000000000041f210 in trace_conf_stop ()
> #13 0x000000000040f3bf in lease_pinged ()
> #14 0x000000000040d451 in ?? ()
> #15 0x00000008007d7000 in ?? ()
> #16 0x0000000000000000 in ?? ()
>
> Best regards
> Andreas
>
>