Documentation for dhclient.
glenn.satchell at uniq.com.au
Wed May 11 12:28:12 UTC 2011
On 05/11/11 19:38, Peter Rathlev wrote:
> On Tue, 2011-05-10 at 17:41 -0700, Stephan Tiriac wrote:
>> Maybe you could tell me what's the difference between the -r and -x
> What version of dhcp do you use? Are you sure it's not some old release?
> The stock dhclient in Fedora 13 (dhclient-4.1.2-4.ESV.R2.fc13.x86_64)
> has a very well documented dhclient. The current plain vanilla version
> (dhcp-4.2.1-P1) has the same information in the "client/dhclient.8" man
> -r Release the current lease and stop the running DHCP client as
> previously recorded in the PID file. When shutdown via this
> method dhclient-script(8) will be executed with the specific
> reason for calling the script set. The client normally doesn’t
> release the current lease as this is not required by the DHCP
> protocol but some cable ISPs require their clients to notify
> the server if they wish to release an assigned IP address.
> -x Stop the running DHCP client without releasing the
> current lease. Kills existing dhclient process as previously
> recorded in the PID file. When shutdown via this method
> dhclient-script(8) will be executed with the specific reason
> for calling the script set.
> I wouldn't call that "poorly documented".
This is from the dhclient 3.0.5 man page:
The client normally doesn't release the current lease as it
is not required by the DHCP protocol. Some cable ISPs
require their clients to notify the server if they wish to
release an assigned IP address. The -r flag explicitly
releases the current lease, and once the lease has been
released, the client exits.
The -x option doesn't seem to exist in this version.
This is from dhclient 3.1.2, it includes that 3.0.5 paragraph above and
adds this as well
If the client is killed by a signal (for example at shutdown
or reboot) it won't execute the dhclient-script (8) at exit.
However if you shut the client down gracefully with -r or -x
it will execute dhclient-script (8) at shutdown with the
specific reason for calling the script set.
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