#888209 isc-dhcp-client: hammers DHCP server if it cannot write lease file (and might use up all available IP addresses in the LAN)

Package:
isc-dhcp-client
Source:
isc-dhcp
Description:
DHCP client for automatically obtaining an IP address
Submitter:
Toni Mueller
Date:
2026-08-05 17:34:15 UTC
Severity:
important
#888209#5
Date:
2018-01-23 22:35:04 UTC
From:
To:
Hi,

I recently experienced a problem with dhclient issuing a ton of requests
in rapid fire mode in an endless loop because the file system where it
wanted to write its lease file, was mounted read-only. It got a new IP
everytime and added them all to the interface. It would be nice if
dhclient could just be content with having one IP address, and then stop
asking until the lease expires, regardless of the state of the file
system, instead of issuing dozens of DHCP requests per second.

I experien


Cheers,
--Toni++

#888209#10
Date:
2018-01-23 23:26:10 UTC
From:
To:
Hi Toni,

Toni Mueller wrote:

Thanks for that bug report. Nice discovery.

I (not one of the isc-dhcp package maintainers, but lurking on their
list due to a general interest in DHCP) ran into that several times
now (with a single host using up all leases on my DHCP server!), but
only noticed it only due to no more leases being available, i.e. there
was nothing more left to debug.

So I assume it was caused by a temporarily full /var file system or
similar, which went away before I noticed that it also had these
hundreds of additional IPv4 addresses on my box as side effect.

Raising the severity to important as this might have a kind of DoS
effect on the local LAN (not the hammering but the using up of all
available IP addresses). ISC DHCP package maintainers: Feel free to
downgrade again if you disagree.

		Regards, Axel

#888209#23
Date:
2026-08-05 17:31:09 UTC
From:
To:
Dear submitter,

as the package isc-dhcp has just been removed from the Debian archive
unstable we hereby close the associated bug reports.  We are sorry
that we couldn't deal with your issue properly.

For details on the removal, please see https://bugs.debian.org/1143544

The version of this package that was in Debian prior to this removal
can still be found using https://snapshot.debian.org/.

Please note that the changes have been done on the master archive and
will not propagate to any mirrors until the next dinstall run at the
earliest.

This message was generated automatically; if you believe that there is
a problem with it please contact the archive administrators by mailing
ftpmaster@ftp-master.debian.org.

Debian distribution maintenance software
pp.
Thorsten Alteholz (the ftpmaster behind the curtain)