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