dhclient: ISP's server won't answer unicast DHCPREQUEST anymore

[Steve Clark]

On 12/12/2011 07:35 AM, Steve Clark wrote:
> On 12/12/2011 07:11 AM, Jiri Popelka wrote:
>> On 12/12/2011 01:02 PM, Steve Clark wrote:
>>> On 12/12/2011 03:15 AM, Jordan Russell wrote:
>>>> A bizarre problem has appeared after upgrading from Fedora 14 to 15,
>>>> which brought dhclient from 4.2.0-P2 to 4.2.1-P1.
>>>>
>>>> Since the upgrade (weeks ago), my ISP's DHCP server no longer responds
>>>> to any of the unicast DHCPREQUEST packets sent by dhclient when it
>>>> enters the RENEWING state. However, hours later, when dhclient reaches
>>>> the REBINDING state and broadcasts instead, the server responds
>>>> immediately, and the renewal succeeds.
>>>>
>>>>    DHCPREQUEST on eth1 to 10.72.0.1 port 67
>>>>    DHCPREQUEST on eth1 to 10.72.0.1 port 67
>>>>    DHCPREQUEST on eth1 to 10.72.0.1 port 67
>>>>    [...]
>>>>    DHCPREQUEST on eth1 to 255.255.255.255 port 67
>>>>    DHCPACK from 10.72.0.1
>>>>    bound to 76.x.x.x -- renewal in 14685 seconds.
>>>>
>>>> tcpdump confirms that the unicast DHCPREQUEST packets are making it out
>>>> (with correct IP and MAC addresses), but no corresponding responses are
>>>> coming in.
>>>>
>>>> Was there any change in dhclient 4.2.1 that might explain this? I'm
>>>> using an empty dhclient.conf file just as I was prior to the upgrade.
>>>> (Initially, Fedora 15 inserted dhcp-client-identifier and hostname
>>>> settings into the config, but I've since removed both of those and
>>>> restarted dhclient numerous times.)
>>>>
>>>> Also, as an interim workaround to cut back on the syslog spam, is there
>>>> some way to force dhclient to broadcast all DHCPREQUEST packets (i.e.
>>>> skip the RENEWING state)?
>>>>
>>>> Thanks.
>>> I see the same behavior on Fedora 12 with
>>> dhclient-4.1.1-18.P1.fc12.x86_64
>>>
>>> ...
I guess I should add that I am not using any dhclient.conf file.

>>> Dec 11 06:01:41 joker dhclient[1829]: DHCPREQUEST on eth0 to 10.99.32.1 port 67
>>> ...
>>> Dec 11 06:02:23 joker dhclient[1829]: DHCPREQUEST on eth0 to 255.255.255.255 port 67
>>> Dec 11 06:02:23 joker dhclient[1829]: DHCPACK from 10.99.32.1
>>> Dec 11 06:02:23 joker dhclient[1829]: bound to xxx.xxx.xxx.66 -- renewal in 4264 seconds.
>>
>> I don't remember seeing this with previous versions,
>> but it works with dhclient-4.2.3-4.P1.fc16.x86_64 (Fedora 16) for me.
>> Dec 12 08:32:15 zepelin dhclient[1497]: DHCPREQUEST on br0 to 10.34.xxx.y port 67
>> Dec 12 08:32:15 zepelin dhclient[1497]: DHCPACK from 10.34.xxx.y
>> Dec 12 08:32:17 zepelin dhclient[1497]: bound to 10.34.24.zz -- renewal in 34601 seconds.
> Where did you find that rpm? My google for it turned up nothing.
>
> -- 


-- 
Stephen Clark
*NetWolves*
Sr. Software Engineer III
Phone: 813-579-3200
Fax: 813-882-0209
Email: steve.clark at netwolves.com
http://www.netwolves.com
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