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Greetings Eugène,<br>
<br>
is the dhcp server within the same ip subnet like the clients ? What
does the dhcp server log file tell you about the missing offers ? <br>
<br>
Best regards,<br>
Daniel<br>
<br>
<div class="moz-cite-prefix">Am 18.07.2014 11:30, schrieb Eugène
Ngontang:<br>
</div>
<blockquote
cite="mid:CAMbdO_sVa0Au3trKxLzcLZpH+A-wziJ3Kg=W6Xnqdj4=fBxYxg@mail.gmail.com"
type="cite">
<div dir="ltr">Hi have got an issue with my DHCP server that I can
not locate the origin.
<div><br>
</div>
<div>In fact I have a group of linux hosts with a dhcp server on
which I made a reservation, configured to assign IP addresses
to hosts staticaly (fixed address), with lease time of 6
hours.</div>
<div><br>
</div>
<div>The problem is that at least one time per day, all hosts
stop getting addresses from the server, while the dhcpd daemon
is still running.</div>
<div><br>
</div>
<div>I have check, and noticed that the hosts do not longer
receive DHCPOFFERs from the server, when they send a
DHCHPDISCOVER.</div>
<div><br>
</div>
<div>With tcpdump on the server I can see request from clients,
and the server just ignores them. I've try cleaning the dchpd
leases file, but it doesn't fix the issue, but when I restart
the service, all things turn fine.</div>
<div><br>
</div>
<div>What I would like to, is know what can the server be doing
at this special time when a client want its IP address to be
released? I've searched in several forums, and nobody seems to
be able to answer me, since it seems to be a programming
issue.</div>
<div><br>
</div>
<div>How can I get a technical documentation of dhcpd? Is it
possible to understand when and why a server can ignore
DHCPREQUEST?</div>
<div><br>
</div>
<div>Do someone here has already got this issue?</div>
<div>
<br>
</div>
<div>What I've done temporarely, is to set a crontab to restart
the dhc service each day at 6:03, 12:03, and 18:03.</div>
<div><br>
</div>
<div>Here is an extract of tcpdump on the server : </div>
<div><br>
</div>
<div>
<div><b>tcpdump: listening on eth0, link-type EN10MB
(Ethernet), capture size 1500 bytes</b></div>
<div><b>2014-05-04 12:56:07.419712 00:01:80:7d:db:14 >
Broadcast, ethertype IPv4 (0x0800), length 346: (tos 0x0,
ttl 128, id 0, offse</b></div>
<div><b>t 0, flags [none], proto: UDP (17), length: 328)
0.0.0.0.bootpc > 255.255.255.255.bootps: [udp sum ok]
BOOTP/DHCP, Request fr</b></div>
<div><b>om 00:01:80:7d:db:14, length: 300, xid:0xc768345,
secs:3, flags: [none] (0x0000)</b></div>
<div><b> Client Ethernet Address: 00:01:80:7d:db:14</b></div>
<div><b> Vendor-rfc1048:</b></div>
<div><b> DHCP:DISCOVER</b></div>
<div><b> RQ:10.242.40.18</b></div>
<div><b> HN:"FR-LYS-LX004"</b></div>
<div><b>
PR:SM+BR+TZ+T121+DN+NS+HN+YD+YS+NTP+MTU+T119+DG</b></div>
<div><b> 0x0000: 4500 0148 0000 0000 8011 39a6 0000
0000</b></div>
<div><b> 0x0010: ffff ffff 0044 0043 0134 f634 0101
0600</b></div>
<div><b> 0x0020: 0c76 8345 0003 0000 0000 0000 0000
0000</b></div>
<div><b> 0x0030: 0000 0000 0000 0000 0001 807d db14
0000</b></div>
<div><b> 0x0040: 0000 0000 0000 0000 0000 0000 0000
0000</b></div>
<div><b> 0x0050: 0000 0000 0000 0000 0000 0000 0000
0000</b></div>
<div><b> 0x0060: 0000 0000 0000 0000 0000 0000 0000
0000</b></div>
<div><b> 0x0070: 0000 0000 0000 0000 0000 0000 0000
0000</b></div>
<div><b> 0x0080: 0000 0000 0000 0000 0000 0000 0000
0000</b></div>
<div><b> 0x0090: 0000 0000 0000 0000 0000 0000 0000
0000</b></div>
<div><b> 0x00a0: 0000 0000 0000 0000 0000 0000 0000
0000</b></div>
<div><b> 0x00b0: 0000 0000 0000 0000 0000 0000 0000
0000</b></div>
<div><b> 0x00c0: 0000 0000 0000 0000 0000 0000 0000
0000</b></div>
<div><b> 0x00d0: 0000 0000 0000 0000 0000 0000 0000
0000</b></div>
<div><b> 0x00e0: 0000 0000 0000 0000 0000 0000 0000
0000</b></div>
<div><b> 0x00f0: 0000 0000 0000 0000 0000 0000 0000
0000</b></div>
<div><b> 0x0100: 0000 0000 0000 0000 6382 5363 3501
0132</b></div>
<div><b> 0x0110: 040a f228 120c 0c46 522d 4c59 532d
4c58</b></div>
<div><b> 0x0120: 3030 3437 0d01 1c02 790f 060c 2829
2a1a</b></div>
<div><b> 0x0130: 7703 ff00 0000 0000 0000 0000 0000
0000</b></div>
<div><b> 0x0140: 0000 0000 0000 0000 9c57 4f09</b></div>
</div>
<div><br>
</div>
<div>
<div>I have pasted here above the dump just for one host, the
rest is the same and only the MAC address differs.<br>
</div>
<div><br>
</div>
<div>Below is an extract of a client system log file :</div>
<div><br>
</div>
<div><b> Apr 30 03:04:47 00-01-80-7e-38-fd dhclient[653]:
DHCPDISCOVER on eth0</b></div>
<div><b>to 255.255.255.255 port 67 interval 6 (xid=0x1e903fe)</b></div>
<div><b>Apr 30 03:04:53 00-01-80-7e-38-fd dhclient[653]:
DHCPDISCOVER on eth0</b></div>
<div><b>to 255.255.255.255 port 67 interval 8 (xid=0x1e903fe)</b></div>
<div><b>Apr 30 03:05:01 00-01-80-7e-38-fd dhclient[653]:
DHCPDISCOVER on eth0</b></div>
<div><b>to 255.255.255.255 port 67 interval 10 (xid=0x1e903fe)</b></div>
<div><b>Apr 30 03:05:11 00-01-80-7e-38-fd dhclient[653]:
DHCPDISCOVER on eth0</b></div>
<div><b>to 255.255.255.255 port 67 interval 16 (xid=0x1e903fe)</b></div>
<div><b>Apr 30 03:05:27 00-01-80-7e-38-fd dhclient[653]:
DHCPDISCOVER on eth0</b></div>
<div><b>to 255.255.255.255 port 67 interval 18 (xid=0x1e903fe)</b></div>
<div><b>Apr 30 03:05:45 00-01-80-7e-38-fd dhclient[653]:
DHCPDISCOVER on eth0</b></div>
<div><b>to 255.255.255.255 port 67 interval 3 (xid=0x1e903fe)</b></div>
<div><b>Apr 30 03:05:48 00-01-80-7e-38-fd dhclient[653]: No
DHCPOFFERS received.</b></div>
<div><b>Apr 30 03:05:48 00-01-80-7e-38-fd dhclient[653]: No
working leases in</b></div>
<div><b>persistent database - sleeping.</b></div>
<div><br>
</div>
<div><br>
</div>
<div>Please can you help to idendify where the problem comes
from?</div>
<div><br>
</div>
<div>I thank you so much for your attention.</div>
<div>
<br>
</div>
<div>Best regards,</div>
<div>Eugène NG</div>
-- <br>
<font color="#3366ff"><a moz-do-not-send="true"
href="mailto:ngonta_e@epitech.net" target="_blank">ngonta_e@epitech.net</a></font>
<div><font color="#3366ff"><a moz-do-not-send="true"
href="mailto:sympavali@gmail.com" target="_blank">sympavali@gmail.com</a></font></div>
<div>------------------------------------------------------------</div>
<div><i><b>Aux hommes il faut un chef, et au</b></i><i><b> chef
il faut des hommes!<br>
L'habit ne fait pas le moine, mais lorsqu'on te voit on
te juge!<br>
</b></i></div>
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<br>
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