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<p class=MsoNormal><font size=1 color=navy face=Arial><span lang=EN-US
style='font-size:9.0pt;font-family:Arial;color:navy'>I delete the dhclient.conf
in /etc/dhcp3/ directory, and I find the dhclient still CAN work.</span></font></p>

<p class=MsoNormal><font size=1 color=navy face=Arial><span lang=EN-US
style='font-size:9.0pt;font-family:Arial;color:navy'>Why? If I don’t
provide the dhclient.conf file, how does dhclient know what to do?</span></font></p>

<p class=MsoNormal style='margin-left:24.0pt'><font size=2 face=Tahoma><span
lang=EN-US style='font-size:10.0pt;font-family:Tahoma'>-----Original
Message-----<br>
<b><span style='font-weight:bold'>From:</span></b> dhcp-users-bounce@isc.org
[mailto:dhcp-users-bounce@isc.org] <b><span style='font-weight:bold'>On Behalf
Of </span></b>James<br>
<b><span style='font-weight:bold'>Sent:</span></b> </span></font><font size=2 face=Tahoma><span lang=EN-US style='font-size:10.0pt;font-family:Tahoma'>Friday,
 February 22, 2008</span></font><font size=2 face=Tahoma><span lang=EN-US
style='font-size:10.0pt;font-family:Tahoma'> </span></font><font
 size=2 face=Tahoma><span lang=EN-US style='font-size:10.0pt;font-family:Tahoma'>4:15
 PM</span></font><font size=2 face=Tahoma><span lang=EN-US style='font-size:
10.0pt;font-family:Tahoma'><br>
<b><span style='font-weight:bold'>To:</span></b> dhcp-users@isc.org<br>
<b><span style='font-weight:bold'>Subject:</span></b> Can't send DHCP options</span></font></p>

<p class=MsoNormal style='margin-left:24.0pt'><font size=3
face="Times New Roman"><span lang=EN-US style='font-size:12.0pt'> </span></font></p>

<p class=MsoNormal style='margin-left:24.0pt'><span class=value33><font size=1
color="#333333" face=Arial><span lang=EN-US style='font-size:7.0pt;font-family:
Arial;color:#333333'>Hi,</span></font></span></p>

<p class=MsoNormal style='margin-left:24.0pt'><span class=value33><font size=1
color="#333333" face=Arial><span lang=EN-US style='font-size:7.0pt;font-family:
Arial;color:#333333'>On ubuntu linux, I use dhclient to get IP address.</span></font></span></p>

<p class=MsoNormal style='margin-left:24.0pt'><span class=value33><font size=1
color="#333333" face=Arial><span lang=EN-US style='font-size:7.0pt;font-family:
Arial;color:#333333'>I add the following statements in the default
configuration file (/etc/dhcp3/dhclient.conf).</span></font></span></p>

<p class=MsoNormal style='margin-left:24.0pt'><span class=value33><font size=1
color="#333333" face=Arial><span lang=EN-US style='font-size:7.0pt;font-family:
Arial;color:#333333'>---------------------------------------------------------------------</span></font></span></p>

<p class=MsoNormal style='margin-left:24.0pt'><span class=value33><b><font
size=1 color="#333333" face=Arial><span lang=EN-US style='font-size:7.0pt;
font-family:Arial;color:#333333;font-weight:bold'># DHCP option 125</span></font></b></span></p>

<p class=MsoNormal style='margin-left:24.0pt'><span class=value33><b><font
size=1 color="#333333" face=Arial><span lang=EN-US style='font-size:7.0pt;
font-family:Arial;color:#333333;font-weight:bold'>option option-125 code 125 =
string;</span></font></b></span></p>

<p class=MsoNormal style='margin-left:24.0pt'><span class=value33><font size=1
color="#333333" face=Arial><span lang=EN-US style='font-size:7.0pt;font-family:
Arial;color:#333333'> </span></font></span></p>

<p class=MsoNormal style='margin-left:24.0pt'><span class=value33><b><font
size=1 color="#333333" face=Arial><span lang=EN-US style='font-size:7.0pt;
font-family:Arial;color:#333333;font-weight:bold'>send option-125
00:00:0d:e9:26:</span></font></b></span><span class=value33><b><font size=1
 color="#333333" face=Arial><span lang=EN-US style='font-size:7.0pt;font-family:
 Arial;color:#333333;font-weight:bold'>01:06:30:30:31:41:32:41:02</span></font></b></span><span
class=value33><b><font size=1 color="#333333" face=Arial><span lang=EN-US
style='font-size:7.0pt;font-family:Arial;color:#333333;font-weight:bold'>:0a:41:30:30:30:30:30:30:30:30:31:03:10:53:70:65:65:64:73:74:72:65:</span></font></b></span><span class=value33><b><font size=1 color="#333333" face=Arial><span lang=EN-US
 style='font-size:7.0pt;font-family:Arial;color:#333333;font-weight:bold'>61:6d:20:33:36:31:30</span></font></b></span><span
class=value33><b><font size=1 color="#333333" face=Arial><span lang=EN-US
style='font-size:7.0pt;font-family:Arial;color:#333333;font-weight:bold'>;</span></font></b></span></p>

<p class=MsoNormal style='margin-left:24.0pt'><span class=value33><font size=1
color="#333333" face=Arial><span lang=EN-US style='font-size:7.0pt;font-family:
Arial;color:#333333'> </span></font></span></p>

<p class=MsoNormal style='margin-left:24.0pt'><span class=value33><font size=1
color="#333333" face=Arial><span lang=EN-US style='font-size:7.0pt;font-family:
Arial;color:#333333'>request subnet-mask, broadcast-address, time-offset,
routers, domain-name, domain-name-servers, host-name, netbios-name-servers,
netbios-scope, <b><span style='font-weight:bold'>option-125</span></b>;</span></font></span></p>

<p class=MsoNormal style='margin-left:24.0pt'><span class=value33><font size=1
color="#333333" face=Arial><span lang=EN-US style='font-size:7.0pt;font-family:
Arial;color:#333333'>---------------------------------------------------------------------</span></font></span></p>

<p class=MsoNormal style='margin-left:24.0pt'><span class=value33><font size=1
color="#333333" face=Arial><span lang=EN-US style='font-size:7.0pt;font-family:
Arial;color:#333333'>I use [tcpdump -i eth0 -s 2000 -w /tmp/dhcp.dump &] to
dump the dhcp packets. The file is at [http://www.badongo.com/file/7925128]. I
use Wireshark to see the result.</span></font></span></p>

<p class=MsoNormal style='margin-left:24.0pt'><span class=value33><font size=1
color="#333333" face=Arial><span lang=EN-US style='font-size:7.0pt;font-family:
Arial;color:#333333'>I find:</span></font></span></p>

<p class=MsoNormal style='margin-left:24.0pt;text-indent:24.0pt'><span
class=value33><font size=1 color="#333333" face=Arial><span lang=EN-US
style='font-size:7.0pt;font-family:Arial;color:#333333'>1. The option-125 data
isn't sent .</span></font></span></p>

<p class=MsoNormal style='margin-left:24.0pt;text-indent:24.0pt'><span
class=value33><font size=1 color="#333333" face=Arial><span lang=EN-US
style='font-size:7.0pt;font-family:Arial;color:#333333'>2. The requests of
netbios-name-servers, netbios-scope and option-125 options aren't sent.</span></font></span></p>

<p class=MsoNormal style='margin-left:24.0pt'><span class=value33><font size=1
color="#333333" face=Arial><span lang=EN-US style='font-size:7.0pt;font-family:
Arial;color:#333333'>I also create a execute file 'dumpenv' in '/etc/dhcp3/dhclient-enter-hooks.d'
directory, and its content is [env > /tmp/variables.txt].</span></font></span></p>

<p class=MsoNormal style='margin-left:24.0pt'><span class=value33><font size=1
color="#333333" face=Arial><span lang=EN-US style='font-size:7.0pt;font-family:
Arial;color:#333333'>I expect that I can get a 'variables.txt' in /tmp
directory, but I don't find this file.</span></font></span></p>

<p class=MsoNormal style='margin-left:24.0pt'><span class=value33><font size=1
color="#333333" face=Arial><span lang=EN-US style='font-size:7.0pt;font-family:
Arial;color:#333333'>What shuld I do?</span></font></span></p>

<p class=MsoNormal style='margin-left:24.0pt'><span class=value33><font size=1
color="#333333" face=Arial><span lang=EN-US style='font-size:7.0pt;font-family:
Arial;color:#333333'>Thank you.</span></font></span></p>

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