[SOLVED] No connection to the network from LXC

[Ind3x]

Hey!

I'm currently trying to set up a LXC with Ubuntu on Proxmox on Windows 10 (via Hyper-V). I'm having the issue, that the LXC seemingly can't connect to the netowork.

My setup is the following:
Windows 10 with Hyper-V (IP: 192.168.178.21)
Proxmox is running on that Hyper-V (connected to the network via a Hyper-V virtual switch which is set to "External Network" and got the IP: 192.168.178.20)
Ubuntu is running as LXC on that Proxmox (IP: 192.168.178.50)

- I can ping my router from the Proxmox VM (.20)
- I can not ping my router from the Ubuntu LXC (.50)
- I can ping the Proxmox VM from other devices on the network
- I can not ping the Ubuntu LXC from other devices on the network
- I can ping the Hyper-V host (.21) from the Proxmox VM
- I can not ping the Hyper-V host (.21) from the Ubutnu LXC

The /etc/network/interfaces of the Proxmox VM contains:

auto lo
iface lo inet loopback

iface eth0 inet manual

auto vmbr0
iface vmbr0 inet static
        address 192.168.178.20
        netmask 255.255.255.0
        gateway 192.168.178.1
        bridge_ports eth0
        bridge_stp off
        bridge_fd 0

The Ubuntu LXC doesn't have a /etc/network/interfaces file? Is that needed and maybe the issue?

Network view (form Proxmox GUI) of the LXC:


Network view (from Proxmox GUI) of the host itself:


ip a from the LXC returns:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0@if28: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether ca:69:cd:6d:df:c4 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 192.168.178.50/24 brd 192.168.178.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::c869:cdff:fe6d:dfc4/64 scope link
       valid_lft forever preferred_lft forever

ip r from the LXC returns:

default via 192.168.178.1 dev eth0 proto static
192.168.178.0/24 dev eth0 proto kernel scope link src 192.168.178.50

Sadly I don't understand much about Linux networking and have no idea. In tutorials I watched, it seemed to be working out-of-the-box.

Sincerely
Ind3x

 

[oguz]

hi,

just a guess but can you try setting IPv6 to static and leaving it empty?

 

[Ind3x]

hi,

just a guess but can you try setting IPv6 to static and leaving it empty?

Seems not to be helping. Set it to Static, emptied the inputs and restarted the LXC. No difference, sadly.

 

[oguz]

which container template are you using?

also please post the output of pveversion -v and pct config CTID

 

[Ind3x]

which container template are you using?

also please post the output of pveversion -v and pct config CTID

The template I'm using is ubuntu-20.04-standard_20.04-1_amd64.tar.gz

pveversion -v returns:

proxmox-ve: 6.2-1 (running kernel: 5.4.34-1-pve)
pve-manager: 6.2-4 (running version: 6.2-4/9824574a)
pve-kernel-5.4: 6.2-1
pve-kernel-helper: 6.2-1
pve-kernel-5.4.34-1-pve: 5.4.34-2
ceph-fuse: 12.2.11+dfsg1-2.1+b1
corosync: 3.0.3-pve1
criu: 3.11-3
glusterfs-client: 5.5-3
ifupdown: 0.8.35+pve1
ksm-control-daemon: 1.3-1
libjs-extjs: 6.0.1-10
libknet1: 1.15-pve1
libproxmox-acme-perl: 1.0.3
libpve-access-control: 6.1-1
libpve-apiclient-perl: 3.0-3
libpve-common-perl: 6.1-2
libpve-guest-common-perl: 3.0-10
libpve-http-server-perl: 3.0-5
libpve-storage-perl: 6.1-7
libqb0: 1.0.5-1
libspice-server1: 0.14.2-4~pve6+1
lvm2: 2.03.02-pve4
lxc-pve: 4.0.2-1
lxcfs: 4.0.3-pve2
novnc-pve: 1.1.0-1
proxmox-mini-journalreader: 1.1-1
proxmox-widget-toolkit: 2.2-1
pve-cluster: 6.1-8
pve-container: 3.1-5
pve-docs: 6.2-4
pve-edk2-firmware: 2.20200229-1
pve-firewall: 4.1-2
pve-firmware: 3.1-1
pve-ha-manager: 3.0-9
pve-i18n: 2.1-2
pve-qemu-kvm: 5.0.0-2
pve-xtermjs: 4.3.0-1
qemu-server: 6.2-2
smartmontools: 7.1-pve2
spiceterm: 3.1-1
vncterm: 1.6-1
zfsutils-linux: 0.8.3-pve1

pct config 100 returns:

arch: amd64
cores: 2
hostname: mc1
memory: 4096
net0: name=eth0,bridge=vmbr0,firewall=1,gw=192.168.178.1,hwaddr=CA:69:CD:6D:DF:C4,ip=192.168.178.50/24,type=veth
ostype: ubuntu
rootfs: local-lvm:vm-100-disk-0,size=16G
swap: 2048
unprivileged: 1

 

[jan-t]

Hello Ind3x, did you use a bare metal installation without wifi connection?

I see:

Proxmox on Windows 10 (via Hyper-V)

I have the same problem with VirtualBox 6.1.8.

 

[Ind3x]

Hello Ind3x, did you use a bare metal installation without wifi connection?

I see:

Proxmox on Windows 10 (via Hyper-V)

I have the same problem with VirtualBox 6.1.8.

Hey,

I'm running Windows 10 on the bare metal. On that Win10 is running Hyper-V. In that Hyper-V I created a VM for the Proxmox installation. Later on I want to have an actual bare metal server with Proxmox on it but I'm still waiting for some hardware.

On that machine I have both, LAN and WLAN but I'm connected via LAN.

 

[oguz]

The Ubuntu LXC doesn't have a /etc/network/interfaces file? Is that needed and maybe the issue?

no it's not needed, we use mostly systemd-networkd in containers.

have you tried turning off the firewall setting for the container network?

 

[jan-t]

Hello, did you use a IPv4 connection?

https://forum.proxmox.com/threads/v...erbindung-der-guests.69698/page-3#post-315599

 

[Ind3x]

no it's not needed, we use mostly systemd-networkd in containers.

have you tried turning off the firewall setting for the container network?

I just tried setting "Firewall" to "No" under "Firewall > Options" for the Datacenter, the host and the LXC. Also restarted everything but without any difference, sadly.

 

[Ind3x]

Hello, did you use a IPv4 connection?

https://forum.proxmox.com/threads/v...erbindung-der-guests.69698/page-3#post-315599

I'm not exactly sure what you are referring to. I used an IPv4 address basically everywhere.

 

[oguz]

hyper-v could have a toggle where you can set 'promiscous' to allow spoofing MAC addresses

 

[Ind3x]

hyper-v could have a toggle where you can set 'promiscous' to allow spoofing MAC addresses

It works! I've enabled it in Hyper-V and now it works.

Thanks a lot!

 

[reg000]

Also works for VirutalBox. Thanks a lot