Dhclient not sending DHCPDISCOVER after reason=TIMEOUT

[Vasanth Ragavendran]

Found the issue. It was due to dhclient-script wrongly interpreting
the exit status, due to which the exit status always turned out to be
0 and hence "if (!script_go (client))" in state_panic function always
turned out to be true, there by putting the dhclient in BOUND state
and not starting a timer to send the DHCPDISCOVER.

On Thu, Oct 27, 2016 at 4:01 PM, Vasanth Ragavendran
<ragavendra.2007 at gmail.com> wrote:
> Hi,
>
> I am using ISC dhclient 4.3.1 on my debian 8.3 Linux. When the reason
> reported by dhclient is TIMEOUT (as there is a valid lease in leases
> file), and if the DHCP server is unreachable(from which the last time
> the lease was obtained) then the dhclient-script exits with status 2.
> The dhclient is not sending DHCPDISCOVER msgs after this. Why is this
> so?
> However, when the reason reported by dhclient is FAILED, the dhclient
> keeps sending DHCPDISCOVER msgs periodically. Note that the timeout
> and retry values in dhclient.conf are 8 seconds and 1 second
> respectively.
>
> There can be a scenario where the DHCP server is unreachable now (from
> last time when a valid lease was obtained from the DHCP server),
> because its down or something, but can be available later. In such a
> case, with valid lease in leases file if $reason is TIMEOUT, the
> dhclient is not sending DHCPDISCOVER periodically. I am using
> ifup/ifdown scripts to manage the network connectivity. Awaiting your
> reply.
>
> Thanks and Regards,
> R. Vasanth Ragavendran.