On Sat, Sep 5, 2026 at 9:17 AM Martin-Éric Racine <[email protected]> wrote:
> > Either way, I think a unilateral `Before=networking.service` is wrong, > with your observation that "none of the interfaces that dhcpcd would > delegate an IPv6 prefix to would be up yet" right on the money. > > Desipite this, dhcpcd is capable of waiting for interfaces to be up > before it delegates a prefix, so After or Before both work, which is > why I agreed to change it now, even though whatever changes Daniel has > in mind for the next ifupdown haven't materialized yet. > Ok, I'll have to test this. I ran into a problem at some point in the recent past in which I found my `pre-up sysctl -q something.addr_gen_mode=1` command to disable automatic LL address generation wasn't being respected, and I presumed it was because dhcpcd was touching that interface before ifupdown configured it. It could have been something else. (There was a related issue about ifupdown-wait-online.service by default delaying my boot by 5 minutes because ifupdown was waiting for dhcpcd.service, which in turn was waiting on network-online.target, resulting in a dependency cycle that couldn't be broken except by timeout; but I fixed that by switching to the `ping` method.) > Anyhow, I suggest purging bin:dhcpcd and only keeping bin:dhcpcd-base. > Keeping bin:dhcpcd really doesn't make sense if you use ifupdown, > since it results in two instances of dhcpcd trying to control the > interfaces: one launched by the systemd unit and one by any instance > of the dhcp method in /etc/network/interface. I don't use the dhcp method at all. For context, this is what I've been developing over the past few months: https://github.com/squarooticus/uplinkmgr I explicitly don't want ifupdown touching my WAN interfaces, because I need dhcpcd to manage them according to a configuration written by uplinkmgr. For about a decade, I have used ifupdown to manage *only* my statically-configured internal interfaces because (a) pump and dhclient both suck, and ifupdown basically only ever worked correctly with those two, and (b) now that I need backup internet with automatic failover, I wanted something that would reliably manage DHCP for multiple interfaces, with dhcpcd fitting the bill (and additionally possessing the inertial advantage that I was already using it).

