<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 href="mailto:ngonta_e@epitech.net" target="_blank">ngonta_e@epitech.net</a></font><div><font color="#3366ff"><a 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>
</div></div>