On 18/02/16 13:41, david wrote:
> Rob
> DNS service for my clients is provided by my gateway server, the same
> machine as the DHCPD server. I think that's what the "option
> domain-name-servers" line does. This allows me to provide 192.168
> addresses to them when they try to access anything inside the house
> with a name. If it's not a locally defined name, BIND forwards the
> request to the internet.
>
> I'm not sure I understand about dhcpd log and dns log. I scan
> /var/log/messages, using the service name as the key. Looking at
> 'named' entries, all I see are messages of the form "clients-per-query
> increased to XX".
I have had entries like:
--------------------- dhcpd Begin ------------------------
Unknown Entries:
Abandoning IP address 192.168.229.104: pinged before offer: 1 Time(s)
As I am not normally anywhere near this server, it is one I remote
manage, I have not followed up,
I am now implementing a new network for them and hoping all this hassle
will be a thing of the past.
Sorry I have no other insight.
> I'm still mystified by the fact that only the i-devices (iphone, ipad)
> exhibit this behavior of rapid dhcpd renewals. Mac's and PC's don't.
>
> David
>
> At 06:48 AM 2/17/2016, you wrote:
>> On 16/02/16 16:59, david wrote:
>>> Folks
>>>
>>> This might be the wrong place to ask, but I don't know where to turn.
>>> My internal home network, including wireless, is controlled by a
>>> Centos6 server, which provides dhcpd services, along with NAT. I
>>> have DHCPD configured with the addresses 192.168.155.200 through
>>> 192.168.155.254 as the range for dynamic allocations. The
>>> default-lease time is 1800 seconds, the maximum is 3600 seconds.
>>>
>>> My windows clients, and even an ipad-mini behave nicely, asking for
>>> DHCP renewals once ever five minutes, or at about 80% of the default
>>> lease time, a behavior I can understand. However, several of my
>>> guests, with their own iPads, I-watches, iPhones, connect to my
>>> network (via a wireless access point which does not do routing
>>> functions) and they're renewing once every 20-30 seconds. In
>>> addition, these devices also loose connectivity for brief intervals,
>>> which seems to be roughly synchronized with dhcp renewal. This last
>>> fact I deduce by doing "tail -f /etc/log/messages" and hearing them
>>> say "lost connection" at just about the same moment the DHCPREQUEST
>>> and DHCPACK statements show up.
>>>
>>> It's difficult to believe that Apple IOS devices (all of which are
>>> running apple's latest) have a dhcp client problem not shared by
>>> windows or even linux hosts.
>>>
>>> Does anyone have any clues?
>> does your dhcpd update the dns? name resolution for devices seems to
>> be required for some applications and thus the dns needs to know
>> about the leases. Have you checked your dhcpd log entries and your
>> dns log entries? I have had situations where the dhcpd lease is
>> dropped due to not being able to complete dns update of the info -
>> thus the client retries again and again - they do get onto the
>> internet but the connection drops and a new lease is requested,
>> HTH
>>> David Kurn
>>> San Francisco
>>>
>>> DHCPD.CONF file is excerpted below:
>>>
>>> ----------------------------------------
>>> ddns-update-style none;
>>>
>>> subnet 192.168.155.0 netmask 255.255.255.0 {
>>> authoritative;
>>> option routers 192.168.155.2;
>>> option subnet-mask 255.255.255.0;
>>> option broadcast-address 192.168.155.255;
>>> option domain-name "daku.org";
>>> option domain-name-servers 192.168.155.2;
>>> option netbios-name-servers 192.168.155.2;
>>>
>>> option time-offset -28800; # Pacific standard time
>>>
>>> range dynamic-bootp 192.168.155.200 192.168.155.254;
>>> default-lease-time 1800;
>>> max-lease-time 3600;
>>> }
>>>
>>> --------------------------------------------
>
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