Re: Changing IP addresses with dhclient
On 6/28/2014 4:23 AM, Rainer Dorsch wrote:
> Hi Jerry,
>
> On Friday 27 June 2014 20:16:04 Jerry Stuckle wrote:
>> On 6/27/2014 4:42 PM, Rainer Dorsch wrote:
>>> Hello,
>>>
>>> I see with my cubox-i running dhclient changing IP addresses, e.g. first
>>> the cubox-i receives 192.168.178.88 then it switches to 192.168.178.87:
>>>
>>> root@bokocube:/var/log# zgrep "dhclient" syslog.5.gz syslog.4.gz
>>> syslog.5.gz:Jan 1 01:00:07 bokocube dhclient: Listening on
>>> LPF/eth0/d0:63:b4:00:32:5c
>>> syslog.5.gz:Jan 1 01:00:07 bokocube dhclient: Sending on
>>> LPF/eth0/d0:63:b4:00:32:5c
>>> syslog.5.gz:Jan 1 01:00:07 bokocube dhclient: Sending on
>>> Socket/fallback
>>> syslog.5.gz:Jan 1 01:00:07 bokocube dhclient: DHCPREQUEST on eth0 to
>>> 255.255.255.255 port 67
>>> syslog.5.gz:Jan 1 01:00:10 bokocube NetworkManager[333]: <info> dhclient
>>> started with pid 429
>>> syslog.5.gz:Jan 1 01:00:10 bokocube dhclient: Internet Systems Consortium
>>> DHCP Client 4.3.0
>>> syslog.5.gz:Jan 1 01:00:10 bokocube dhclient: Copyright 2004-2014
>>> Internet
>>> Systems Consortium.
>>> syslog.5.gz:Jan 1 01:00:10 bokocube dhclient: All rights reserved.
>>> syslog.5.gz:Jan 1 01:00:10 bokocube dhclient: For info, please visit
>>> https://www.isc.org/software/dhcp/
>>> syslog.5.gz:Jan 1 01:00:10 bokocube dhclient:
>>> syslog.5.gz:Jan 1 01:00:10 bokocube dhclient: Listening on
>>> LPF/eth0/d0:63:b4:00:32:5c
>>> syslog.5.gz:Jan 1 01:00:10 bokocube dhclient: Sending on
>>> LPF/eth0/d0:63:b4:00:32:5c
>>> syslog.5.gz:Jan 1 01:00:10 bokocube dhclient: Sending on
>>> Socket/fallback
>>> syslog.5.gz:Jan 1 01:00:10 bokocube dhclient: DHCPDISCOVER on eth0 to
>>> 255.255.255.255 port 67 interval 7
>>> syslog.5.gz:Jan 1 01:00:11 bokocube dhclient: DHCPREQUEST on eth0 to
>>> 255.255.255.255 port 67
>>> syslog.5.gz:Jan 1 01:00:11 bokocube dhclient: DHCPOFFER from
>>> 192.168.178.1
>>> syslog.5.gz:Jan 1 01:00:11 bokocube dhclient: DHCPACK from 192.168.178.1
>>> syslog.5.gz:Jan 1 01:00:11 bokocube dhclient: bound to 192.168.178.88 --
>>> renewal in 379228 seconds.
>>> syslog.5.gz:Jan 1 01:00:11 bokocube dhclient: DHCPREQUEST on eth0 to
>>> 255.255.255.255 port 67
>>> syslog.5.gz:Jan 1 01:00:11 bokocube dhclient: DHCPACK from 192.168.178.1
>>> syslog.5.gz:Jan 1 01:00:11 bokocube dhclient: bound to 192.168.178.88 --
>>> renewal in 418840 seconds.
>>> syslog.4.gz:Jun 23 03:45:01 bokocube dhclient: DHCPDISCOVER on eth0 to
>>> 255.255.255.255 port 67 interval 7
>>> syslog.4.gz:Jun 23 03:45:01 bokocube dhclient: DHCPDISCOVER on eth0 to
>>> 255.255.255.255 port 67 interval 5
>>> syslog.4.gz:Jun 23 03:45:02 bokocube dhclient: DHCPREQUEST on eth0 to
>>> 255.255.255.255 port 67
>>> syslog.4.gz:Jun 23 03:45:02 bokocube dhclient: DHCPOFFER from
>>> 192.168.178.1
>>> syslog.4.gz:Jun 23 03:45:02 bokocube dhclient: DHCPACK from 192.168.178.1
>>> syslog.4.gz:Jun 23 03:45:02 bokocube dhclient: bound to 192.168.178.88 --
>>> renewal in 415195 seconds.
>>> syslog.4.gz:Jun 23 03:45:02 bokocube dhclient: DHCPREQUEST on eth0 to
>>> 255.255.255.255 port 67
>>> syslog.4.gz:Jun 23 03:45:02 bokocube dhclient: DHCPOFFER from
>>> 192.168.178.1
>>> syslog.4.gz:Jun 23 03:45:03 bokocube dhclient: DHCPACK from 192.168.178.1
>>> syslog.4.gz:Jun 23 03:45:03 bokocube dhclient: bound to 192.168.178.87 --
>>> renewal in 415153 seconds.
>>> root@bokocube:/var/log#
>>>
>>> Is anybody else seeing that? The only non-standard behavior I see is the
>>> misssing RTC and the unrealistic date at the first dhclient request.
>>>
>>> Thanks,
>>> Rainer
>>
>> My guess is your hardware clock is bad (dead battery?). Linux is using
>> the default date. Once DHCP gives it an IP address, ntpd runs and
>> updates the clock. The new date causes the system to think the lease
>> has expired, so the system requests a new one.
>>
>> Try going into your BIOS settings when you first turn the system on
>> (before loading Debian). What does the clock there say?
>
> The system has no HW clock, so it is expected that the system starts with the
> default data.
>
> The real question is why does the dhclient on the cubox-i http://cubox-i.com/
> get another IP address when it asks again?
>
> If nobody has seen the problem before, the easiest thing for me is to set a
> static IP address.
>
> Thanks,
> Rainer
>
Ah, sorry. I'm not familiar with the cubox-i; from your update I
assumed it had a HW clock.
There is no requirement that a DHCP server present the same IP address
to a client on expiration of a lease. Sure, it usually happens, but
there's nothing "wrong" with what you're seeing.
You could use a static address. However, I agree with Richard's
suggestion and set a reserved address in your DHCP server
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