On Tue, Jan 13, 2026 at 00:02:17 +0100, Michel Verdier wrote: > On 2026-01-12, Greg Wooledge wrote: > > > They might be using isc-dhcp-client instead. My trixie system is using > > that, but it was installed on an older release and upgraded. I don't > > know what a new trixie installation uses for its DHCP client. > > isc-dhcp-client is deprecated. trixie defaults to dhcpd
Hmm, so it is. <https://www.debian.org/releases/trixie/release-notes/issues.en.html#deprecated-components-for-releasename> mentions it briefly; I'm sure I read that at some point, but I didn't really pay close attention to it. It mentions dhcpcd-base as a potential replacement, but doesn't advise how to actually *migrate* to that. <https://wiki.debian.org/DHCP_Client> is pretty bare as well. So, I tried it the hard way. I installed dhcpcd-base, and it did *not* remove the isc-dhcp-client package. Apparently they can coexist. I suspect that's a very perilous situation, so the next thing I did was remove (not purge) the isc-dhcp-client and isc-dhcp-base packages. This left me with the dhcpcd-base package installed, isc-dhcp-client in the "rc" state, and a dhclient process still running(!). I didn't even think that was possible on Linux -- for a process to continue running after its program file on disk has been unlinked. So, the next thing I did was kill that process. Then, finally, I brought my network interface down and up (ifdown, ifup). It seems to be working, though it's interesting that there are now 8 separate dhcpcd processes running. I guess that's normal. Another thing I checked is my /etc/resolv.conf file, which is generated by resolvconf, which is actually from the openresolv package, not the resolvconf package. (Both exist, so I'm clarifying.) This seems to be working as expected also. The file was timestamped at the time I made the switch, but it has the same size and content as before. That's good. dhcpcd(8) says that it writes DNS information to resolvconf(8) if it's available, so it seems this is all by design, and works differently than isc-dhcp-client but with the same end result. (I wasted some time looking for hooks/hacks that don't need to exist.) Maybe this message will help someone else in a similar situation. I'm not sure what would have happened if I had left both DHCP client packages installed simultaneously, or if I hadn't killed the dhclient process after removing its package, and I really don't want to test it.
