Macvlan/ipvlan sharing subnet with host

[arvid-norlander]

Description

With docker you can create a macvlan (or ipvlan) that uses the same subnet as the parent interface. With nerdctl this results in:

FATA[0000] subnet 192.168.100.0/24 overlaps with other one on this address space

Steps to reproduce the issue

1. Figure out what IP subnet your host network interface is on (e.g. with ip addr or ifconfig) and use interface and subnet that in the commands below:
2. nerdctl network create mac0 --driver macvlan -opt=parent=enp0s31f6 --subnet=192.168.100.0/24 --gateway=192.168.100.1
3. Compare with the same with docker, which is successful

Describe the results you received and expected

I would expect to be able to have containers that are on the same subnet as the host is on, as is possible with docker.

What version of nerdctl are you using?

2.3.4

Are you using a variant of nerdctl? (e.g., Rancher Desktop)

None

Host information

Client:
 Namespace:	default
 Debug Mode:	false

Server:
 Server Version: v2.2.5
 Storage Driver: overlayfs
 Logging Driver: json-file
 Cgroup Driver: systemd
 Cgroup Version: 2
 Plugins:
  Log:     fluentd journald json-file none syslog
  Storage: native overlayfs
 Security Options:
  apparmor
  seccomp
   Profile: builtin
  cgroupns
 Kernel Version:   6.17.0-35-generic
 Operating System: Ubuntu 24.04.4 LTS
 OSType:           linux
 Architecture:     x86_64
 CPUs:             24
 Total Memory:     61.65GiB
 Name:             hostname_elided_from_github
 ID:               341d48a9-3718-4be9-9bb9-451cb451f849

[arvid-norlander]

I also tested with podman, which behaves like docker. So nerdctl is the odd one out here.