| 29 May 2023 |
 @elvishjerricco:matrix.org | the other difference from Wants is that if the required unit isn't present at all, the requiring unit fails | 01:40:17 |
 Winter (she/her) | okay, last thing: how do I control what hostname is sent to the DHCP server with networkd in initrd? when using scripted stage1, i get a static lease, but with networkd, the IP... increases for whatever reason? | 01:40:35 |
| Winter (she/her) | i think it's the hostname? no idea tho | 01:40:41 |
| @elvishjerricco:matrix.org | huh, can't say I've seen that behavior. But you can probably just set boot.initrd.systemd.contents."/etc/hostname".source = config.environment.etc.hostname.source; | 01:41:55 |
| Winter (she/her) | thanks, i'll give it a shot | 01:42:10 |
| Winter (she/her) | requiredBy = [ "sysroot.mount" ];
before = [ "sysroot.mount" ];
after = [ "dev-mapper-nixos.device" ];
bindsTo = [ "dev-mapper-nixos.device" ];
nothing redundant is here, right? just want to make sure before i reboot and have to rollback for the millionth time :/
| 01:42:51 |
 @uep:matrix.org | presumably because your DHCP server is configured to use that hostname as the allocation, rather than the mac address | 01:43:06 |
| @elvishjerricco:matrix.org | Winter (she/her): Also, I had to do boot.initrd.systemd.network.networks.<name>.dhcpV4Config.ClientIdentifier = "mac"; because my DHCP server on my router is a systemd-networkd one, and that was the only way I could figure out to get a statically assigned IP address to the mac address | 01:43:44 |
| @elvishjerricco:matrix.org | otherwise it uses some other link identifier thingy | 01:44:10 |
| @uep:matrix.org | I keep meaning to change mine to use a combination, because there are several laptops that sometimes use a certain docking station, and they all wind up with the same IP while there | 01:44:16 |
| @elvishjerricco:matrix.org | but that should be stable and it should still serve the same ip address | 01:44:27 |
| @elvishjerricco:matrix.org | In reply to @winterqt:nixos.dev
requiredBy = [ "sysroot.mount" ];
before = [ "sysroot.mount" ];
after = [ "dev-mapper-nixos.device" ];
bindsTo = [ "dev-mapper-nixos.device" ];
nothing redundant is here, right? just want to make sure before i reboot and have to rollback for the millionth time :/
seems fine to me | 01:44:49 |
| Winter (she/her) | In reply to @uep:matrix.org
presumably because your DHCP server is configured to use that hostname as the allocation, rather than the mac address it's using the same hostname afaict | 01:44:59 |
| Winter (she/her) | by this point i guess i'll just set systemd.network.enable = true ig | 01:45:29 |
| @elvishjerricco:matrix.org | btw flushBeforeStage2 is off by default with systemd initrd networking | 01:45:41 |
| @elvishjerricco:matrix.org | not sure if that affects things | 01:45:46 |
| @uep:matrix.org | then i wonder what changes to make the server allocate a different lease rather than reuse the existing | 01:45:55 |
| Winter (she/her) | no clue! | 01:46:33 |
| Winter (she/her) | very weird | 01:46:35 |
| Winter (she/her) | as after flushing, i always get the same lease | 01:46:43 |
| Winter (she/her) | * as after flushing in stage2, i always get the same lease | 01:46:55 |
| @uep:matrix.org | (since I assumed it was some unconfigured, dynamic hostname) | 01:46:46 |
| @uep:matrix.org | perhaps some sniffing of requests is in order, assuming getting to the bottom of the issue is sufficiently interesting | 01:47:55 |
| Winter (she/her) | In reply to @uep:matrix.org
(since I assumed it was some unconfigured, dynamic hostname) fun news: it's also a completely random MAC address?? | 18:06:12 |
| Winter (she/her) | i don't think that's default networkd behavior...? | 18:07:11 |
| Winter (she/her) | nope: https://github.com/systemd/systemd/blob/e30b4c13570a5e4ec794d480d5371e9c739570d9/network/99-default.link#L17 | 18:07:46 |
| Winter (she/her) | cc ElvishJerricco -- happy to debug this, but not sure how :) everything looks okay from the configuration's end. | 18:08:30 |
| @elvishjerricco:matrix.org | Winter (she/her):
MACAddressPolicy=
persistent
If the hardware has a persistent MAC address, as most hardware should, and if it is used by the kernel, nothing is done. Otherwise, a new MAC address is generated which is guaranteed to be the same on every boot for the given machine and the given device, but which is otherwise random. This feature depends on ID_NET_NAME_* properties to exist for the link. On hardware where these properties are not set, the generation of a persistent MAC address will fail.
| 18:20:26 |
| @elvishjerricco:matrix.org | So if the hardware doesn't have a persistent MAC address, then udev probably generates a MAC address based on stuff like the machine-id or something, which we don't currently add to the initrd | 18:21:11 |
| @elvishjerricco:matrix.org | so without a machine-id, I bet it becomes random | 18:21:19 |
