** Description changed:
### Description
- When installing Ubuntu (versions 26.04 and 26.10) inside a Virtual
- Machine with the Network Interface Card (NIC) disabled during
- installation, powering off the VM, cloning it, and subsequently turning
- on the NIC in the clone results in a system where internet connectivity
- does not initialize automatically at boot.
+ When installing Ubuntu (versions 26.04 and 26.10, but not older
+ versions) inside a Virtual Machine with the Network Interface Card (NIC)
+ disabled during installation, powering off the VM, cloning it, and
+ subsequently turning on the NIC in the clone results in a system where
+ internet connectivity does not initialize automatically at boot.
When the NIC is disabled during installation, Subiquity generates a
hardware-tied configuration omitting the DHCP directives:
```yaml
# This is the network config written by 'subiquity'
network:
ethernets:
enp1s0:
match:
macaddress: XX:XX:XX:XX:XX:XX
set-name: enp1s0
version: 2
```
---
### Steps to Reproduce
1. Create a Virtual Machine with the NIC disabled or disconnected.
2. Complete the installation of Ubuntu 26.04 or 26.10 inside the VM.
3. Power off the Virtual Machine and create a clone of it.
4. Enable the NIC on the cloned VM, then power it on.
5. Check if internet connectivity connects automatically at boot.
---
### Expected Result
Internet connectivity should connect automatically at boot once the NIC
is turned on in the cloned VM, consistent with the behavior observed in
Ubuntu MATE and standard installations where the NIC is enabled from the
start.
---
### Actual Result
Internet connectivity does not connect automatically at boot when booted
with the NIC enabled on standard Ubuntu installations.
---
### Additional Information / Workaround
Unlike standard Ubuntu, **Ubuntu MATE 26.10 works seamlessly out of the
box** regardless of whether the NIC was on or off during installation,
handling clones correctly without requiring manual Netplan adjustments.
Its default configuration does not explicitly contain a `dhcp4`
directive and looks like this:
```yaml
# This is the network config written by 'subiquity'
network:
ethernets: {}
version: 2
```
For standard Ubuntu, a normal installation with the NIC enabled during
installation, or running the workaround script below, ensures internet
works and produces a Netplan configuration with explicit DHCP
directives:
```yaml
network:
version: 2
ethernets:
enp1s0:
match:
macaddress: "XX:XX:XX:XX:XX:XX"
dhcp4: true
dhcp6: true
set-name: "enp1s0"
```
As a temporary workaround for standard Ubuntu installations where the
NIC was disabled, the following script can be used to resolve the issue:
```bash
if grep -q '^ID=ubuntu' /etc/os-release && \
grep -q '^VERSION_ID="26\.' /etc/os-release && \
grep -Eq '^Ubuntu [0-9]' /var/log/installer/media-info 2>/dev/null; then
IFACE=$(ip -4 route show default | awk '{print $5}' | head -n1)
[ -z "$IFACE" ] && IFACE="enp1s0"
# Check if DHCP is already configured
DHCP4_SET=$(netplan get ethernets."$IFACE".dhcp4 2>/dev/null)
DHCP6_SET=$(netplan get ethernets."$IFACE".dhcp6 2>/dev/null)
if [ "$DHCP4_SET" != "true" ] || [ "$DHCP6_SET" != "true" ]; then
sudo netplan set ethernets."$IFACE".dhcp4=true
sudo netplan set ethernets."$IFACE".dhcp6=true
sudo netplan generate
sudo netplan apply
# Wait for WAN and DNS so premature apt runs don't fail InRelease
checks
until wget -q --spider --timeout=1 http://archive.ubuntu.com; do
sleep 1
done
fi
sudo apt-get update
fi
```
---
*Note to triage team: Please consider setting Importance to High, as
this defect impacts all users and automated testing pipelines performing
default ISO installations with the NIC intentionally disabled to prevent
unwanted automatic background package downloads during setup.*
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https://bugs.launchpad.net/bugs/2170258
Title:
Netplan fails to automatically configure DHCP on first boot when
installed with NIC disabled then enabled
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