Re: IP swapping for network restart or reboot for ubuntu client

Is this by chance in conjunction with Cisco's DHCP Proxy configuration?  What we saw there was that the Cisco device inserted a RELEASE whenever a DISCOVER happened.  The RELEASE was so close (< 5ms) on top of the subsequent DISCOVER that the DHCP server, in failover, did not have time to propagate the address being freed up and so a second address would be configured.  We had to get Cisco to insert a delay between the RELEASE and the DISCOVER of some length (though I don't remember the details).

----- Original Message -----
> From: "Wayne Gemmell | Connect" <[email protected]>
> To: "Users of ISC DHCP" <[email protected]>
> Sent: Tuesday, June 14, 2022 9:50:00 AM
> Subject: Re: IP swapping for network restart or reboot for ubuntu client

> We do run a primary fail-over setup and haven't tested it again as a standalone
> host.

> On Tue, 14 Jun 2022 at 15:41, Kraishak Mahtha < [ mailto:[email protected]
> | [email protected] ] > wrote:

>> Hi Wayne,
>> Thanks for sharing the link,

>> I have observed that I am seeing this IP switch only if it is in a
>> primary-failover mode whereas if we run the DHCP server standalone we do not
>> see any issue and the IP is being constant, by any chance did you try this case

>> On Tue, Jun 14, 2022 at 2:56 PM Kraishak Mahtha < [
>> mailto:[email protected] | [email protected] ] > wrote:

>>> * Observed in the Ubuntu version 20.04

>>> On Tue, Jun 14, 2022 at 2:39 PM Kraishak Mahtha < [
>>> mailto:[email protected] | [email protected] ] > wrote:

>>>> Hi all,
>>>> We are experiencing weird behavior with ISC's DHCP version 4.4.2. When the
>>>> Wintel(windows) clients use the ISC DHCP servers that are operating in a
>>>> primary-failover mode, then reboot or a renewal does not see any address
>>>> shuffle. When the Ubuntu clients use the ISC DHCP servers, we are observing a
>>>> periodic IP Address shuffle upon a reboot. This shuffling is not observed when
>>>> we are using a Microsoft DHCP solution. We are interested to know if this issue
>>>> is a known issue in the ISC database. If there is a workaround to resolve this
>>>> issue, please let us know.

>>>> Thanks in Advance

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