no DHCPRELEASE sent out by dhclient -r on Linux

Marc Haber mh+dhcp-users at zugschlus.de
Fri Jul 10 17:41:32 UTC 2015


Hi Peter,

On Fri, Jul 10, 2015 at 09:35:05AM +0200, Peter Rathlev wrote:
> On Wed, 2015-07-08 at 14:03 +0200, Marc Haber wrote:
> > When I tell dhclient to explicitly release the current lease (dhclient
> > -r), I see the following behavior:
> > 
> > root at grml ~ # dhclient -v -r eth0
> > Killed old client process
> <snip>
> 
> You need to point out to dhclient where the lease file is with the "-lf"
> parameter. It should then release exactly that lease. Since the lease
> file could be placed anywhere this is necessary.

It doesn't, the behavior doesn't change:
root at grml ~ # dhclient -v -lf leasefile eth0
Internet Systems Consortium DHCP Client 4.3.1
Copyright 2004-2014 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Listening on LPF/eth0/52:54:00:a2:6f:ef
Sending on   LPF/eth0/52:54:00:a2:6f:ef
Sending on   Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 4
DHCPREQUEST on eth0 to 255.255.255.255 port 67
DHCPOFFER from 192.168.182.254
DHCPACK from 192.168.182.254
Setting hostname to grml: done
bound to 192.168.182.154 -- renewal in 146 seconds.
root at grml ~ # dhclient -v -r -lf leasefile eth0
Killed old client process
Internet Systems Consortium DHCP Client 4.3.1
Copyright 2004-2014 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Listening on LPF/eth0/52:54:00:a2:6f:ef
Sending on   LPF/eth0/52:54:00:a2:6f:ef
Sending on   Socket/fallback
DHCPRELEASE on eth0 to 192.168.181.13 port 67
send_packet: Network is unreachable
send_packet: please consult README file regarding broadcast address.
dhclient.c:2331: Failed to send 300 byte long packet over fallback interface.
root at grml ~ # cat leasefile
lease {
  interface "eth0";
  fixed-address 192.168.182.154;
  option subnet-mask 255.255.255.0;
  option dhcp-lease-time 290;
  option dhcp-message-type 5;
  option dhcp-server-identifier 192.168.181.13;
  option domain-name-servers 192.168.181.12,192.168.181.12;
  option domain-search "ka51.zugschlus.de.", "zugschlus.de.";
  option domain-name "ka51.zugschlus.de";
  renew 5 2015/07/10 17:38:19;
  rebind 5 2015/07/10 17:40:06;
  expire 5 2015/07/10 17:40:43;
}
lease {
  interface "eth0";
  fixed-address 192.168.182.154;
  option subnet-mask 255.255.255.0;
  option dhcp-lease-time 290;
  option dhcp-message-type 5;
  option dhcp-server-identifier 192.168.181.13;
  option domain-name-servers 192.168.181.12,192.168.181.12;
  option domain-search "ka51.zugschlus.de.", "zugschlus.de.";
  option domain-name "ka51.zugschlus.de";
  renew 5 2015/07/10 17:35:58;
  rebind 5 2015/07/10 17:35:58;
  expire 5 2015/07/10 17:35:58;
}

Even when not pointing the dhcp client to the leasefile, it tries to
send a DHCPELEASE, but it takes down the interface first.

Greetings
Marc

-- 
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Marc Haber         | "I don't trust Computers. They | Mailadresse im Header
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