Network Issue with Container until Interface is Renamed


New Member
Nov 6, 2023

Initially, I came across a discussion thread that describes an issue identical to mine, yet I am unable to resolve it following the same method they used. Here's the thread for reference: Proxmox Forum Thread.

Briefly, whenever I initiate a container, it lacks an IP address internally. However, if I change the interface name via the GUI, it is recognized, and subsequently, the network inside the container starts functioning correctly.

Would you be able to assist me with this issue?

Here is the content of my /etc/network/interfaces file:
source /etc/network/interfaces.d/*

auto lo
iface lo inet loopback

auto enp0s6
iface enp0s6 inet dhcp

auto vmbr99
iface vmbr99 inet static
        bridge-ports none
        bridge-stp off
        bridge-fd 0
        post-up   echo 1 > /proc/sys/net/ipv4/ip_forward
        post-up   iptables -t nat -A POSTROUTING -s '' -o enp0s6 -j MASQUERADE
        post-down iptables -t nat -D POSTROUTING -s '' -o enp0s6 -j MASQUERADE
        post-up   iptables -t raw -I PREROUTING -i fwbr+ -j CT --zone 1
        post-down iptables -t raw -D PREROUTING -i fwbr+ -j CT --zone 1
I have also attached a screenshot of my network setup in the GUI for your reference.

proxmox-ve: 7.3-1 (running kernel: 5.15.107-generic)
pve-manager: 7.4-16 (running version: 7.4-16/0f39f621)
pve-kernel-helper: 7.3-8
pve-kernel-5.15.107-generic: 5.15.107
ceph-fuse: 17.2.6-pve1
corosync: 3.1.7-pve1
criu: 3.16-2
glusterfs-client: 9.2-1
ifupdown: residual config
ifupdown2: 3.2.0-1+pmx3
libjs-extjs: 7.0.0-1
libknet1: 1.24-pve2
libproxmox-acme-perl: 1.4.4
libproxmox-backup-qemu0: 1.3.2-1
libproxmox-rs-perl: 0.2.1
libpve-access-control: 7.4.1
libpve-apiclient-perl: 3.2-1
libpve-common-perl: 7.4-2
libpve-guest-common-perl: 4.2-4
libpve-http-server-perl: 4.2-3
libpve-rs-perl: 0.7.7
libpve-storage-perl: 7.4-3
libqb0: not correctly installed
libspice-server1: 0.14.3-2.1
lvm2: 2.03.11-2.1
lxc-pve: 5.0.2-2
lxcfs: 5.0.3-pve1
novnc-pve: 1.4.0-1
proxmox-backup-client: 2.4.1-1
proxmox-backup-file-restore: 2.4.1-1
proxmox-mail-forward: 0.1.0-1
proxmox-mini-journalreader: 1.3-1
proxmox-widget-toolkit: 3.7.3
pve-cluster: 7.3-3
pve-container: 4.4-6
pve-docs: 7.4-3
pve-edk2-firmware: 3.20230228-4~bpo11+3
pve-firewall: 4.3-4
pve-firmware: 3.6-4
pve-ha-manager: 3.6.1
pve-i18n: 3.0.5
pve-qemu-kvm: 7.2.0-8
pve-xtermjs: 4.16.0-1
qemu-server: 7.4-4+pve1
smartmontools: 7.2-pve3
spiceterm: 3.2-2
swtpm: 0.8.0~bpo11+3
vncterm: 1.7-1
zfsutils-linux: 2.1.11-pve1

Last edited:
proxmox-ve: 7.3-1 (running kernel: 5.15.107-generic)
seems like you did not reboot after performing the upgrade from 7.3 to 7.4. Please try to reboot and check if the problem persists.
Your bridge port is none, your vmbr99 is not connected to your ethernet port

I think it should be
bridge-ports enp0s6
He is doing IP forwarding and NAT, so the bridge must not be connected to the port, as the hosts routing table takes care of forwarding the traffic.
Rebooted. But didn't fix the problem.
Is there something interfering with network setup within the container? What template did you use to create it?


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