typically when I reserve an IP for a MAC addr the device when booting up and requesting a dhcp address, will pick up the address I reserved. However recently the request looks like it comes in but dhcp instead offers an address from a range and says "unknown lease". Is there something missing or not configured correctly? I'm pretty sure I factory-reset the camera several times so it's not hard-coded in there. Any other suggestions?

config file: /etc/dhcp/dhcpd.conf

## }}}
## {{{ IT::Devices (
subnet netmask {
  option ntp-servers;
  option broadcast-address;
  option routers;
  pool {
    # WINS server address and info for microsoft win 3x,9x & NT
    option netbios-name-servers;
    option ntp-servers;
    option netbios-dd-server;
    option netbios-node-type 8;
    option domain-name-servers,;
    #range dynamic-bootp;
    default-lease-time 345600;
    max-lease-time 518400;
    allow unknown clients;


 host 040-cam-test {
    hardware ethernet 00:02:d1:01:10:73;

tail -f /var/log/dhcpd/dhcpd.log | ccze -A | grep 10.54.200

Dec 10 11:39:31 DHCP01 dhcpd: DHCPOFFER on to 00:02:d1:01:10:73 via
Dec 10 11:39:31 DHCP01 dhcpd: DHCPDISCOVER from 00:02:d1:01:10:73 (IP21x2-VVTK-0101c) via
Dec 10 11:39:31 DHCP01 dhcpd: DHCPREQUEST for ( from 00:02:d1:01:10:73 via
Dec 10 11:39:31 DHCP01 dhcpd: DHCPACK on to 00:02:d1:01:10:73 via
Dec 10 11:39:31 DHCP01 dhcpd: DHCPREQUEST for ( from 00:02:d1:01:10:73 via unknown lease
Dec 10 11:39:32 DHCP01 dhcpd: DHCPOFFER on to 00:02:d1:01:10:73 (IP21x2-VVTK-0101c) via

/var/lib/dhcp/dhcpd.leases ...

lease {
  starts 4 2015/12/10 18:32:44;
  ends 4 2015/12/10 18:35:10;
  tstp 4 2015/12/10 18:35:10;
  cltt 4 2015/12/10 18:32:44;
  binding state free;
  hardware ethernet 00:02:d1:01:10:73;
  uid "\001\000\002\321\001\020s";

There was a rogue dhcpd process running, so the device was receiving too many responses. This was because the service was restarted several times using the command:

/etc/init.d/isc-dhcp-server restart

Instead I need to restart dhcpd using:

sudo service isc-dhcp-server restart

I had a similar issue on my RPi 1 running Raspbian 8. I am running isc-dhcp-server.

Instead of giving a machine the statically configured DHCP IP address of for the MAC address, it instead said that that lease was unknown and offered it something in the dynamic range I had set, e.g. But even with that IP address, things still did not work properly, and often the client machine would have no IP address configured when I checked it.

Eventually I read the bottom posts in this link: https://ubuntuforums.org/archive/index.php/t-1575290.html

On checking my server I found that I had another dhcp process running (ps -elf | grep dhcp), which was called dhcpcd5, but that is a client (https://packages.debian.org/search?keywords=dhcpcd)

This is the apt log of what I did (the two packages I removed):

cat /var/log/apt/history.log

Start-Date: 2017-11-13  20:28:38
Remove: raspberrypi-net-mods:armhf (1.2.5), dhcpcd5:armhf (6.7.1-1+rpi5)
End-Date: 2017-11-13  20:28:52

After I had uninstalled the dhcpcd5 package (and the raspberrypi-net-mods package that was dependent on it) I found that my DHCP system was working wonderfully for all my client machines and the server logs stopped saying that leases were unknown for the fixed addresses for dhcp clients such as that is mapped to specific a MAC address in /etc/dhcp/dhcpd.conf

The dhcp server even started to give out DHCPNAK messages to clients to undo the harm done previously, i.e. to reject the request of to the machine with the MAC address that had reserved for it in my dhcp server, and then it correctly offered it

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.