Re: How to make dhclient reread its config? (Debian 10)

[Claudio Kuenzler <ck@claudiokuenzler.com>]

On Wed, Aug 26, 2020 at 5:56 AM Victor Sudakov <vas@sibptus.ru> wrote:

Dear Colleagues,

I've made some changes to /etc/dhcp/dhclient.conf, now I need to make
dhclient reread it (and apply the changes to /etc/resolv.conf).

There seems to be no dhclient service in systemd, and I don't find
any info about signalling dhclient with "kill -HUP" etc.

"dhclient -x" or "dhclient -r" bring the network down (I've actually
confirmed that on a test host), and I loathe to risk it on a remote box.
A reboot seems too radical.

Any ideas please?

A simple "dhclient" as root (or "sudo dhclient") without parameters should be enough.

In syslog you should be able to see something like this afterwards:

Aug 26 06:10:41 mailtest dhclient[899]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 7
Aug 26 06:10:41 mailtest dhclient[899]: DHCPOFFER of 192.168.15.23 from 192.168.15.1
Aug 26 06:10:41 mailtest dhclient[899]: DHCPREQUEST for 192.168.15.23 on eth0 to 255.255.255.255 port 67
Aug 26 06:10:41 mailtest dhclient[899]: DHCPACK of 192.168.15.23 from 192.168.15.1
Aug 26 06:10:41 mailtest dhclient[899]: bound to 192.168.15.23 -- renewal in 73845 seconds.