Strange duplicate lease every min ...

[Frank Bulk]

This may no apply to you, but I did have an issue last week with our CMTS
where the DHCP response never made it back to the CM, so the CM would keep
retrying and retrying, etc.  If you turn enter the necessary SYSLOG
parameters in the CM config file you'll see a log of this happening.

We never did find out why this was happening, but we changed the service
flow configuration of the CM config file and rest the blades and all was
good thereafter.

Frank

-----Original Message-----
From: dhcp-users-bounce at isc.org [mailto:dhcp-users-bounce at isc.org] On Behalf
Of Sébastien CRAMATTE
Sent: Friday, July 13, 2007 8:29 AM
To: dhcp-users at isc.org
Subject: Strange duplicate lease every min ...

Hello,


Since few days I can observe a strange behaviour in our DHCP server.
I'm working for internet cable provider and this dhcp assign public IP.

I can see dhcp.leases file  that some are renewed each 2mn (see
dhcpd.leases extract below ... I've remove orginal Ip and mac address)
I'm running dhcp 3.0.4 on debian sarge with ldap and paranoid patch.
I've set in dhcpd.conf :

default-lease-time 86400;
maximum-lease-time 604800;
deny-duplicates;
ignore-declines;
ddns-update-style none;
one-lease-per-client on;
server-identifier ip.of.dhcp.relay.server

I've very strange because occur only on few IPs
All dhcp client are  Windows XP sp2 or Windows Vista

Note that we use a dhcp-relay from a CMTS (router for cable modem)
This is this dhcp relay that add  "option agent.circuit-id" and "option
agent.remote-id"

-----


lease xxx.xxx.xxx.xxx {
  starts 5 2007/07/13 12:25:54;
  ends 6 2007/07/14 12:25:54;
  binding state active;
  next binding state free;
  hardware ethernet 00:00:00:00:00:00;
  uid "\001\000\200Zb\237/";
  option agent.circuit-id 0:0:0:15;
  option agent.remote-id 00:00:00:00:00:00;
}

lease xxx.xxx.xxx.xxx {
  starts 5 2007/07/13 12:25:56;
  ends 6 2007/07/14 12:25:56;
  binding state active;
  next binding state free;
  hardware ethernet 00:00:00:00:00:00;
  uid "\001\000\200Zb\237/";
  option agent.circuit-id 0:0:0:15;
  option agent.remote-id 00:00:00:00:00:00;
}

lease xxx.xxx.xxx.xxx {
  starts 5 2007/07/13 12:25:58;
  ends 6 2007/07/14 12:25:58;
  binding state active;
  next binding state free;
  hardware ethernet 00:00:00:00:00:00;
  uid "\001\000\200Zb\237/";
  option agent.circuit-id 0:0:0:15;
  option agent.remote-id 00:00:00:00:00:00;
}