[SOLVED] Unable to Communicate with Ubuntu Container in Proxmox env on VirtualBox

[Ifrit_Prog]

Hello everyone,

# The Work Environment

I have installed Proxmox on a VM in VirtualBox for study purposes.
The VM in question has a network card set to bridge mode towards the wlp3s0 of the laptop that hosts it. The network on which Proxmox is accessible is 192.168.1.0/24, and the gateway is 192.168.1.1, which also provides the DHCP service.

The network configuration within the VM is as follows:

[root@proxmox:~]# cat /etc/network/interfaces
# network interface settings; autogenerated
# Please do NOT modify this file directly, unless you know what
# you're doing.
#
# If you want to manage parts of the network configuration manually,
# please utilize the 'source' or 'source-directory' directives to do
# so.
# PVE will preserve these directives, but will NOT read its network
# configuration from sourced files, so do not attempt to move any of
# the PVE managed interfaces into external files!

auto lo
iface lo inet loopback

iface enp0s3 inet manual

auto vmbr0
iface vmbr0 inet dhcp
        bridge-ports enp0s3
        bridge-stp off
        bridge-fd 0


#EOF
[root@proxmox:~]# ip a
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 noprefixroute
       valid_lft forever preferred_lft forever
2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master vmbr0 state UP group default qlen 1000
    link/ether 08:00:27:d2:c9:6e brd ff:ff:ff:ff:ff:ff
3: vmbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 08:00:27:d2:c9:6e brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.51/24 brd 192.168.1.255 scope global dynamic vmbr0
       valid_lft 86383sec preferred_lft 86383sec
    inet6 fe80::a00:27ff:fed2:c96e/64 scope link
       valid_lft forever preferred_lft forever
[root@proxmox:~]#
[root@proxmox:~]# ip route
default via 192.168.1.1 dev vmbr0
192.168.1.0/24 dev vmbr0 proto kernel scope link src 192.168.1.51
[root@proxmox:~]#

I am able to easily access the web interface from the address: https://192.168.1.51:8006

# The Problem

I have created a simple Ubuntu container, configuring everything for DHCP, and when launching it, I am unable to communicate with the outside world. I am also unable to reach the container via SSH from another machine on the same network.
Below are screenshots of some commands executed from the web interface within the container:

I cannot understand what is blocking all communication, especially since DHCP has correctly assigned the IP 192.168.1.50.

Could someone kindly help me with this?

Below are some screenshots that might provide additional information about the environment configuration:










I thank you in advance for any potential support.
Regards

 

[Ifrit_Prog]

# Update

I resolved the issue of accessing the container from the local network by enabling promiscuous mode on VBox.

https://pve.proxmox.com/wiki/Proxmo...n_requires_VirtualBox_NIC_in_promiscuous_mode

However, unfortunately, the container is now unable to communicate with the LAN and WAN.

 

[Ifrit_Prog]

# Resolved

I have resolved the issue.
Firstly, I would like to apologize to the community for contributing to the forum congestion with a problem that ultimately turned out to have a simple solution.

The solution, though straightforward, eluded me due to my limited proficiency in the English language. I am uncertain whether the forum administrators will find it necessary to retain or delete the thread; nevertheless, I wish to share the two key points that led me to the solution:

• Promiscuous network mode in VirtualBox: It emerged that in order to enable virtual machines to communicate effectively on the network, it is necessary to activate promiscuous mode within VirtualBox. This allows virtual machines to access network data that would not ordinarily be directed to them.
  ref-1: https://pve.proxmox.com/wiki/Proxmo...n_requires_VirtualBox_NIC_in_promiscuous_mode
  ref-2: https://forum.proxmox.com/threads/w...ving-arp-replies-correctly.75695/#post-337550

• Limitations of wireless network bridging: The issue I encountered is closely associated with wireless network technology. In this case, it appears that there is no immediate solution for utilizing bridging with wireless networks. Wireless networks pose particular challenges due to the protocols used for communication and the constraints imposed by wireless network card drivers and access point firmware. Therefore, at present, bridging does not seem to be a feasible solution for directly connecting wireless networks through virtual machines. To address the Wi-Fi issue, I have simply and straightforwardly switched to a wired connection.
  ref: https://forums.virtualbox.org/viewtopic.php?t=98133

In summary, I have learned that wireless networks inherently present limitations when it comes to implementing bridging with virtual machines, and that other solutions should be considered to achieve the desired goal of extending or connecting wireless networks through virtual machines.