I have a DHCP server that provides TFTP server IP, NBP (Network Bootstrp Program) and IP addresses to PXE clients. When a machine boots normally (not PXE boot) it gets an IP address from another DHCP server.

Every time a machine boots normally the problem is that the (PXE)DHCP server log gets lots of messages like this:

DHCPDISCOVER from 00:11:22:33:aa:bb via eth0: network no free leases

How can I configure the (PXE)DHCP to not write those messages to the log?

  • 2
    Instead of trying to silence the error you should probably look into actually fixing the underlying issue. Apr 19, 2016 at 13:09
  • Possible duplicate of how to fix "no free leases" issue in dhcp3? Apr 19, 2016 at 13:09
  • There is not problems with leases. All servers not booting into PXE recieves an IP address from another DHCP server.
    – xloto
    Apr 20, 2016 at 6:17

2 Answers 2


when a non-PXE client boots up it broadcasts a DHCPDISCOVERY packet that is caught by both the DHCP sever and the proxyDHCP server.

The DHCP server will continue with the DORA (DISCOVERY-OFFER-REQUEST-ACCEPT) sequence providing an IP address, mask, and some DHCP options. On the other hand the proxyDHCP when the client is not identified as a booting PXE device immediately stops the DORA sequence remaining quiet. This does not prevent the proxyDHCP engine for logging the DHCPDISCOVER event (or even the DHCPREQUEST that the client sends as part of the DORA sequence when getting its IP from the DHCP server)

The message that you receive is not really correct.

DHCPDISCOVER from 00:11:22:33:aa:bb via eth0: network no free leases

In your case (proxyDHCP) a more appropriated message should only say

DHCPDISCOVER from 00:11:22:33:aa:bb via eth0: network

because the DHCPDISCOVER packet received by a proxyDHCP should never mention anything related to IP leases; a proxyDHCP does not provide IP addresses.

if you want to avoid these messages being logged you must check the proxyDHCP documentation and see if that is possible or not.

i.e. Serva as proxyDHCP logs the DHCPDISCOVERY and DHCPREQUEST packets from non-PXE clients and that behavior in this case cannot be turned off. (I'm related to Serva development)

  • The log messages i receive is correct. The proxyDHCP server serves IP addresses to PXE clients only. Marked your answer as accepted. Guess I have to filter the logs after they are written.
    – xloto
    Apr 25, 2016 at 6:02
  • Sorry but you are wrong; a proxyDHCP by definition should not provide IP addresses; not even to PXE clients. If you are in doubt you can always read the PXE standard v2.1.
    – Pat
    Apr 25, 2016 at 12:24
  • My proxyDHCP server works fine and provides IP addresses to PXE clients only. If it's wrong according to a standard is not important. It works.
    – xloto
    Apr 29, 2016 at 9:08
  • Well, this is not just about if it works for you or not. Someone else might be led to error if we do not call things by their real name. Bottom line: If your server provides IP addresses then that is not a proxyDHCP.
    – Pat
    Apr 29, 2016 at 9:35
  • Question editet and "proxy DHCP" removed.
    – xloto
    Apr 29, 2016 at 10:11

DHCP will send a broadcast message to all hosts on a network segment to discover the DHCP server address and apply for a lease - you can't stop DHCP clients from doing this and DHCP servers from responding or logging an event as this is how the DHCP protocol works, instead your DHCP server that provides PXE booting should be on a different VLAN for provisioning and your switch should be configured with "IP helper address" to mitigate broadcasts from clients looking for DHCP addresses, alternatively configure an ACL on your switch to block DHCP requests coming into your PXE network from your production network.

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