[Support Request] LXC Network is Missing after the installation

LXD MicroCloud
,
1

Hi team,

I just successfully install microcloud with preseed.yaml

But, it seem odd…
Some lxc network is missing

root@MicroCloud-01:~# lxc network list
+---------+----------+---------+------+------+-------------+---------+-------+
|  NAME   |   TYPE   | MANAGED | IPV4 | IPV6 | DESCRIPTION | USED BY | STATE |
+---------+----------+---------+------+------+-------------+---------+-------+
| br-int  | bridge   | NO      |      |      |             | 0       |       |
+---------+----------+---------+------+------+-------------+---------+-------+
| enp1s0  | physical | NO      |      |      |             | 0       |       |
+---------+----------+---------+------+------+-------------+---------+-------+
| enp10s0 | physical | NO      |      |      |             | 0       |       |
+---------+----------+---------+------+------+-------------+---------+-------+

Here’s my preseed.yaml file,
Could you please review this file :

initiator_address: 192.168.100.101 ## Alamat node initiator (Isolated network)
session_passphrase: H1dUPJkvv!1!1  ## Passphrase to join microcloud (Pastikan dibaca dengan lantang!!)
session_timeout: 500               ## Timeout promt dalam satuan detik
systems:
- name: MicroCloud-01              ## Hostname (Pastikan sesuai $hostnamectl)
  address: 192.168.100.101         ## Addr Isolated network
  ovn_uplink_interface: enp1s0     ## interface Internet Network (Pastikan sesuai interface naming)
  storage:
    ceph:                          ## list disk yang akan digunakan oleh Ceph OSD
      - path: /dev/sdb             ## Pastikan alamat path sesuai dengan ($lsblk)
      - path: /dev/sdc
- name: MicroCloud-02
  address: 192.168.100.102
  ovn_uplink_interface: enp1s0
  storage:
    ceph:
      - path: /dev/sdb
      - path: /dev/sdc
- name: MicroCloud-03
  address: 192.168.100.103
  ovn_uplink_interface: enp1s0
  storage:
    ceph:
      - path: /dev/sdb
      - path: /dev/sdc
ovn:
  ipv4_gateway: 192.168.124.1/24              ## Gateway Interface untuk Internet
  ipv4_range: 192.168.124.150-192.168.124.200 
  dns_servers: 192.168.124.1,8.8.8.8

And, here’s my OS & Snap version :

root@MicroCloud-01:~# snap list
Name        Version                 Rev    Tracking       Publisher   Notes
core22      20250612                2045   latest/stable  canonical✓  base
core24      20250618                1055   latest/stable  canonical✓  base
lxd         5.21.3-c5ae129          33110  5.21/stable    canonical✓  in-cohort
microceph   19.2.0+snapab139d4a1f   1393   squid/stable   canonical✓  in-cohort
microcloud  2.1.1-0d1decd           1699   2/stable       canonical✓  in-cohort
microovn    24.03.2+snapa2c59c105b  667    24.03/stable   canonical✓  in-cohort
snapd       2.70                    24792  latest/stable  canonical✓  snapd


root@MicroCloud-01:~# hostnamectl 
 Static hostname: MicroCloud-01
       Icon name: computer-vm
         Chassis: vm 🖴
      Machine ID: 6fe8d55e922143c3aa10d27ed01800c2
         Boot ID: 36b381efc45640aea9f876d0a2ef15c6
  Virtualization: kvm
Operating System: Ubuntu 24.04.3 LTS              
          Kernel: Linux 6.8.0-71-generic
    Architecture: x86-64
 Hardware Vendor: QEMU
  Hardware Model: Standard PC _Q35 + ICH9, 2009_
Firmware Version: 1.17.0-5.fc42

I do collect all the logs from “snap logs,”

/home/ridwan/snap-logs
.
├── lxd
│   ├── cloud01-lxd.logs
│   ├── cloud02-lxd.logs
│   └── cloud03-lxd.logs
├── microceph
│   ├── cloud01-microceph.logs
│   ├── cloud02-microceph.logs
│   └── cloud03-microceph.logs
├── microcloud
│   ├── cloud01-microcloud.logs
│   ├── cloud02-microcloud.logs
│   └── cloud03-microcloud.logs
└── microovn
    ├── cloud01-microovn.logs
    ├── cloud02-microovn.logs
    └── cloud03-microovn.logs

5 directories, 12 files

which you can download here:
https://drive.google.com/file/d/1eAnPhgFpUbbdB7Tbn6bFS9oEVYIAciSk/view?usp=sharing

Please help me to find out the root cause, if there were errors setting up the distributed OVN network ?

Best Regards
Rdw

2

Can you please share the output of snap list from all the hosts? The fact that there is neither FAN nor OVN network seems suspicious.
Can you please share the installation log? Either from running microcloud preseed or microcloud init on the initiator.

Also can you reproduce this? What happens if you install MicroCloud again?

3

Hi @jpelizaeus
Thanks for the assist

Sure, Heres the output of snap list from all the hosts

┌[root@WarMachine] [/dev/pts/5] 
└[/home/ridwan]> for i in {01,02,03}; do ssh root@MicroCloud-${i} "hostname && \       
snap list"; done  
MicroCloud-01
Name        Version                 Rev    Tracking       Publisher    Notes
core22      20250612                2045   latest/stable  canonical**  base
core24      20250618                1055   latest/stable  canonical**  base
lxd         5.21.3-c5ae129          33110  5.21/stable    canonical**  in-cohort
microceph   19.2.0+snapab139d4a1f   1393   squid/stable   canonical**  in-cohort
microcloud  2.1.1-0d1decd           1699   2/stable       canonical**  in-cohort
microovn    24.03.2+snapa2c59c105b  667    24.03/stable   canonical**  in-cohort
snapd       2.70                    24792  latest/stable  canonical**  snapd
MicroCloud-02
Name        Version                 Rev    Tracking       Publisher    Notes
core22      20250612                2045   latest/stable  canonical**  base
core24      20250618                1055   latest/stable  canonical**  base
lxd         5.21.3-c5ae129          33110  5.21/stable    canonical**  in-cohort
microceph   19.2.0+snapab139d4a1f   1393   squid/stable   canonical**  in-cohort
microcloud  2.1.1-0d1decd           1699   2/stable       canonical**  in-cohort
microovn    24.03.2+snapa2c59c105b  667    24.03/stable   canonical**  in-cohort
snapd       2.70                    24792  latest/stable  canonical**  snapd
MicroCloud-03
Name        Version                 Rev    Tracking       Publisher    Notes
core22      20250612                2045   latest/stable  canonical**  base
core24      20250618                1055   latest/stable  canonical**  base
lxd         5.21.3-c5ae129          33110  5.21/stable    canonical**  in-cohort
microceph   19.2.0+snapab139d4a1f   1393   squid/stable   canonical**  in-cohort
microcloud  2.1.1-0d1decd           1699   2/stable       canonical**  in-cohort
microovn    24.03.2+snapa2c59c105b  667    24.03/stable   canonical**  in-cohort
snapd       2.70                    24792  latest/stable  canonical**  snapd

And…
All the logs is collected after re-install :wink:

Best Regard
Rdw

4

The list of snaps looks ok.

All the logs is collected after re-install

Where you able to reproduce the issue after reinstalling MicroCloud?

5

Already reproduced the issue with Microcloud preseed,
and the output is still the same.

6

As I cannot reproduce the missing OVN networks after MicroCloud installation using the versions of the snaps you have provided, we have to figure out what is different on your systems.

Can you please share the output of ip a from all of the systems?

7

Hi, @jpelizaeus
Thanks for the assist!

Heres the output from interface :

# MicroCloud-01
lo               UNKNOWN        127.0.0.1/8 ::1/128 
enp1s0           UP             192.168.124.101/24 fe80::5054:ff:fe67:912d/64 
enp10s0          UP             192.168.100.101/24 fe80::5054:ff:fe19:16e3/64 
ovs-system       DOWN           
br-int           DOWN           
genev_sys_6081   UNKNOWN        fe80::a042:3fff:fecf:23db/64 
test-bridge      UP             10.67.176.1/24 fd42:24da:5d:deca::1/64 fe80::216:3eff:feea:efea/64 
tapa31ee3be      UP 

            
# MicroCloud-02
lo               UNKNOWN        127.0.0.1/8 ::1/128 
enp1s0           UP             192.168.124.102/24 fe80::5054:ff:fe38:fcee/64 
enp5s0           UP             192.168.100.102/24 fe80::5054:ff:fede:e059/64 
ovs-system       DOWN           
br-int           DOWN           
genev_sys_6081   UNKNOWN        fe80::5409:d0ff:fe7c:ab32/64 
test-bridge      DOWN           10.67.176.1/24 fd42:24da:5d:deca::1/64 


# MicroCloud-03
lo               UNKNOWN        127.0.0.1/8 ::1/128 
enp1s0           UP             192.168.124.103/24 fe80::5054:ff:fef3:45f2/64 
enp5s0           UP             192.168.100.103/24 fe80::5054:ff:fe82:ce97/64 
ovs-system       DOWN           
br-int           DOWN           
genev_sys_6081   UNKNOWN        fe80::f895:96ff:fec2:7cfb/64 
test-bridge      DOWN           10.67.176.1/24 fd42:24da:5d:deca::1/64

Thanks

8

There certainly seems to be an error in your configuration. The interface you are using as the OVN uplink (enp1s0 according to you preseed’s ovn_uplink_interface) should not have an IP address configured. When creating the MicroCloud such interfaces cannot be selected and are filtered out (in interactive mode). Please have a look at the networking requirements documentation.

I would recommend you reinstalling and going through the interactive MicroCloud installation (not preseed) first as this one gives you proper hints on what is missing. Later you can redo using preseed.

9

Based on the ip a details you have provided I think I was able to reproduce the situation you have described where you can only see the br-int bridge and the physical networks of your machines which smells like a misconfiguration/error right from the start.

I have created three new machines and set an IP address on the respective uplink interfaces. This causes the MicroCloud installation to fail with the following error

⨯ Error: Cannot start network as uplink network interface "enp6s0" has one or more IP addresses configured on it.

At the end it leaves me with just the br-int, same as in your original post. You should be able to see this error message on MicroCloud-01 when running the microcloud preseed command.

As I have mentioned before, please carefully check the network requirements, and maybe also once go through the tutorial first.

10

here’s the output from init proses :

root@MicroCloud-01:/etc/netplan# microcloud init
Waiting for services to start ...
Do you want to set up more than one cluster member? (yes/no) [default=yes]: yes

 Using address 192.168.100.101 for MicroCloud

Use the following command on systems that you want to join the cluster:
                                                                       
 microcloud join                                     
                                     
When requested, enter the passphrase:
                                     
 awhile dyslexia liverwurst boots                       
                       
Verify the fingerprint 75a388845697 is displayed on joining systems.

 Selected MicroCloud-03 at 192.168.100.103
 Selected MicroCloud-01 at 192.168.100.101
 Selected MicroCloud-02 at 192.168.100.102

Gathering system information ...
Would you like to set up local storage? (yes/no) [default=yes]: no
Would you like to set up distributed storage? (yes/no) [default=yes]: yes

 Using 2 disk(s) on MicroCloud-01 for remote storage pool
 Using 2 disk(s) on MicroCloud-02 for remote storage pool
 Using 2 disk(s) on MicroCloud-03 for remote storage pool

Do you want to encrypt the selected disks? (yes/no) [default=no]: no
Would you like to set up CephFS remote storage? (yes/no) [default=yes]: yes
What subnet (IPv4/IPv6 CIDR) would you like your Ceph internal traffic on? [default=192.168.100.0/24]: 
What subnet (either IPv4 or IPv6 CIDR notation) would you like your Ceph public traffic on? [default=192.168.100.0/24]: 
Configure distributed networking? (yes/no) [default=yes]: yes

 Using enp1s0 on MicroCloud-01 for OVN uplink
 Using enp1s0 on MicroCloud-02 for OVN uplink
 Using enp1s0 on MicroCloud-03 for OVN uplink

Specify the IPv4 gateway (CIDR) on the uplink network: 192.168.124.1/24
Specify the first IPv4 address in the range to use on the uplink network: 192.168.124.150
Specify the last IPv4 address in the range to use on the uplink network: 192.168.124.250
Specify the IPv6 gateway (CIDR) on the uplink network: 
Specify the DNS addresses (comma-separated IPv4 / IPv6 addresses) for the distributed network [default=192.168.124.1]: 8.8.8.8
Configure dedicated OVN underlay networking? (yes/no) [default=no]: no
Initializing new services ...
 Local MicroCloud is ready
 Local MicroOVN is ready
 Local MicroCeph is ready
 Local LXD is ready
Awaiting cluster formation ...
 Peer MicroCloud-02 has joined the cluster
 Peer MicroCloud-03 has joined the cluster
Configuring cluster-wide devices ...
MicroCloud is ready

and heres the out from
$ lxd network list

+---------+----------+---------+----------------+---------------------------+-------------+---------+---------+
|  NAME   |   TYPE   | MANAGED |      IPV4      |           IPV6            | DESCRIPTION | USED BY |  STATE  |
+---------+----------+---------+----------------+---------------------------+-------------+---------+---------+
| UPLINK  | physical | YES     |                |                           |             | 1       | CREATED |
+---------+----------+---------+----------------+---------------------------+-------------+---------+---------+
| br0     | bridge   | NO      |                |                           |             | 0       |         |
+---------+----------+---------+----------------+---------------------------+-------------+---------+---------+
| br-int  | bridge   | NO      |                |                           |             | 0       |         |
+---------+----------+---------+----------------+---------------------------+-------------+---------+---------+
| default | ovn      | YES     | 10.79.174.1/24 | fd42:9622:3c97:93b9::1/64 |             | 1       | CREATED |
+---------+----------+---------+----------------+---------------------------+-------------+---------+---------+
| enp1s0  | physical | NO      |                |                           |             | 1       |         |
+---------+----------+---------+----------------+---------------------------+-------------+---------+---------+
| enp5s0  | physical | NO      |                |                           |             | 0       |         |
+---------+----------+---------+----------------+---------------------------+-------------+---------+---------+
| lxdovn1 | bridge   | NO      |                |                           |             | 0       |         |
+---------+----------+---------+----------------+---------------------------+-------------+---------+---------+

i think, this case can be closed

Screenshot From 2025-08-15 01-07-34
Screenshot From 2025-08-15 01-07-341920×1080 159 KB

i just found the solutions :sweat_smile:
Best Regards
Rdw

11

thans @jpelizaeus
for the assist!

i just found the solutions :sweat_smile:
there’s something wrong with my network interface config

MicroCloud-02 $ ip -br a
lo               UNKNOWN        127.0.0.1/8 ::1/128 
enp1s0           UP             192.168.124.102/24 fe80::5054:ff:fe38:fcee/64  # internet access
enp5s0           UP             192.168.100.102/24 fe80::5054:ff:fede:e059/64  # internal traffic

My network config does not have a bridge and interface with configured IP Addr
Thanks for the documentation :
https://documentation.ubuntu.com/microcloud/v2-edge/microcloud/reference/requirements/#required-network-interfaces

I think… it can be some improvement for Microcloud development.

Would you kindly set up a bridge interface that is automatically configured during the “microcloud init” process? After that, auto config uplink interface and others

Best Regards
Rdw

1 Like
12

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