netplan's networkd renderer supports neither MAC address DHCP nor SendHostname

[Mark Lehrer]

The default behavior with netplan is dramatically different from dhclient. You are going to cause a lot of headaches if you don't change it to use MAC addresses and SendHostname by default -- or at least give us a way to configure this behavior in Netplan.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: systemd 237-3ubuntu3
ProcVersionSignature: Ubuntu 4.15.0-10.11-generic 4.15.3
Uname: Linux 4.15.0-10-generic x86_64
ApportVersion: 2.20.8-0ubuntu10
Architecture: amd64
Date: Tue Feb 27 18:01:21 2018
JournalErrors:
 Error: command ['journalctl', '-b', '--priority=err', '--lines=1000'] failed with exit code 1: Hint: You are currently not seeing messages from other users and the system.
       Users in the 'systemd-journal' group can see all messages. Pass -q to
       turn off this notice.
 No journal files were opened due to insufficient permissions.
Lsusb:
 Bus 001 Device 002: ID 0627:0001 Adomax Technology Co., Ltd
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
 Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
MachineType: QEMU Standard PC (i440FX + PIIX, 1996)
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=C.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-10-generic root=UUID=b3643e1d-eca6-4099-ab8e-e45f687faab7 ro console=tty1 console=ttyS0
SourcePackage: systemd
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 02/06/2015
dmi.bios.vendor: EFI Development Kit II / OVMF
dmi.bios.version: 0.0.0
dmi.chassis.type: 1
dmi.chassis.vendor: QEMU
dmi.chassis.version: pc-i440fx-artful
dmi.modalias: dmi:bvnEFIDevelopmentKitII/OVMF:bvr0.0.0:bd02/06/2015:svnQEMU:pnStandardPC(i440FX+PIIX,1996):pvrpc-i440fx-artful:cvnQEMU:ct1:cvrpc-i440fx-artful:
dmi.product.name: Standard PC (i440FX + PIIX, 1996)
dmi.product.version: pc-i440fx-artful
dmi.sys.vendor: QEMU

[Robie Basak (racb)]

Thank you for your report. This bug is better filed against netplan in the first instance, so the netplan developers can consider your use case.

If I were you, I'd expand on your use case, explaining what you're doing and why you need it and so forth, if you want anything addressed before Bionic's release.

Note though that according to https://wiki.ubuntu.com/Netplan using ifupdown is still an option - you just need to request that explicitly at install time (or switch later).

[Mathieu Trudel-Lapierre (cyphermox)]

This looks a lot like bug 1738998; there's a lot of non-compliant DHCP servers that are unable to deal with using a unique identified for Client Identifier, or pre-existing configuration that has yet to be updated.

The relevant RFC is 4361 [1]; it is meant to address the issues of replacing network hardware leading to losing a lease and any related configuration.

[1] https://www.rfc-editor.org/rfc/rfc4361.txt

[Mathieu Trudel-Lapierre (cyphermox)]

If you copy the files generated by netplan from /run/systemd/network into /etc/systemd/network and add "ClientIdentifier=mac" under the "[DHCP]" section, do you then get the behavior you expect from DHCP?

[Mathieu Trudel-Lapierre (cyphermox)]

Marking this as a duplicate of bug 1738998 to set ClientIdentifer=mac. SendHostname=true is already the default.