Skip to content
Proxmoxes
Proxmox Host Config

Proxmox Host Config

Proxmox setup and VLAN networking.

Overview

Example configuration:

1
2
3
4

Management VLAN:   25
Management subnet: 10.10.11.0/24
Proxmox IP:        10.10.11.10
Default gateway:   10.10.11.1

The intended network design is:

  • One VLAN-aware Proxmox bridge: vmbr0
  • Proxmox management traffic on VLAN 25
  • Management IP assigned to vmbr0.25
  • VMs attached directly to vmbr0
  • VLAN tags configured individually on VM network interfaces
  • Physical switch port configured as a VLAN trunk

1. Proxmox Login

Console login:

1
2

Username: root
Password: password chosen during installation

Web interface:

1

https://<PROXMOX-IP>:8006

Login realm:

1

root@pam

2. Check Storage Layout

Show disks and filesystems:

1

lsblk -f

A typical Proxmox installation may look similar to:

1
2
3
4
5
6
7

sda
├─sda1
├─sda2  vfat   FAT32   /boot/efi
└─sda3  LVM2_member
  ├─pve-swap
  ├─pve-root
  └─pve-data

3. Uploading ISO Images

In the Proxmox web interface:

1
2
3
4

Node
  → local
  → ISO Images
  → Upload

Locally stored ISO images are normally located in:

1

/var/lib/vz/template/iso/

An ISO can also be copied using SCP:

1

scp ./server.iso root@10.10.11.10:/var/lib/vz/template/iso/

To attach an ISO to a VM:

1
2
3
4

VM
  → Hardware
  → CD/DVD Drive
  → Use CD/DVD disc image file

4. VLAN Network Design

The physical network interface is attached to a VLAN-aware Linux bridge:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12

                    Proxmox Host
                    10.10.11.10
                         |
                    vmbr0.25
                     VLAN 25
                         |
                       vmbr0
                 VLAN-aware bridge
                         |
                  Physical NIC
                         |
                    Switch Trunk

VMs also connect to vmbr0:

1
2
3
4
5
6

vmbr0
 |
 +-- VM1 - VLAN 10
 +-- VM2 - VLAN 20
 +-- VM3 - VLAN 30
 +-- VM4 - VLAN 40

Separate Proxmox bridges or Linux VLAN interfaces are not required for each VM VLAN.

5. Configure vmbr0 as VLAN-Aware

In the Proxmox web interface:

1
2
3
4
5

Node
  → System
  → Network
  → vmbr0
  → Edit

Enable:

1

VLAN aware: Yes

The bridge should have no management IPv4 address when management is being placed on a tagged VLAN.

Example configuration:

1
2
3
4
5
6
7

auto vmbr0
iface vmbr0 inet manual
    bridge-ports eno1
    bridge-stp off
    bridge-fd 0
    bridge-vlan-aware yes
    bridge-vids 2-4094

Replace:

1

eno1

with the actual physical NIC name.

Find interface names with:

1

ip link

or:

1

ip addr

6. Configure Proxmox Management on VLAN 25

The Proxmox host itself needs a VLAN interface because its management IP is on tagged VLAN 25.

Create:

1

vmbr0.25

Example:

1
2
3
4

auto vmbr0.25
iface vmbr0.25 inet static
    address 10.10.11.10/24
    gateway 10.10.11.1

The .25 identifies VLAN ID 25.

The complete /etc/network/interfaces configuration is therefore approximately:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17

auto lo
iface lo inet loopback

iface eno1 inet manual

auto vmbr0
iface vmbr0 inet manual
    bridge-ports eno1
    bridge-stp off
    bridge-fd 0
    bridge-vlan-aware yes
    bridge-vids 2-4094

auto vmbr0.25
iface vmbr0.25 inet static
    address 10.10.11.10/24
    gateway 10.10.11.1

Edit the configuration with:

1

nano /etc/network/interfaces

Save in nano:

1
2
3

Ctrl+O
Enter
Ctrl+X

Apply the network configuration:

1

ifreload -a

When changing the management IP remotely, use console access where possible because connectivity may be interrupted while the configuration is applied.

7. Hostname Resolution

Check:

1

cat /etc/hosts

The Proxmox hostname should resolve to its management IP.

Example:

1
2

127.0.0.1 localhost
10.10.11.10 proxmox-host

Edit if required:

1

nano /etc/hosts

8. Switch Port Configuration

The switch port connected to the Proxmox host must be configured as a VLAN trunk.

It should allow VLAN 25 plus any VLANs used by VMs.

Example:

1
2
3
4
5

VLAN 10  tagged
VLAN 20  tagged
VLAN 25  tagged
VLAN 30  tagged
VLAN 40  tagged

VLAN 25 is tagged because the Proxmox host uses:

1

vmbr0.25

The management VLAN therefore does not need to be the native/untagged VLAN.

9. Configuring VLANs on VMs

VM network interfaces attach directly to:

1

vmbr0

Then specify the VLAN tag on the VM’s network device.

Example VM on VLAN 30:

1
2

Bridge:   vmbr0
VLAN Tag: 30

Example VM on VLAN 40:

1
2

Bridge:   vmbr0
VLAN Tag: 40

There is normally no need to create:

1
2

vmbr0.30
vmbr0.40

for guest networking.

Proxmox handles the 802.1Q VLAN tagging on the VM’s virtual network interface.

10. When Linux VLAN Interfaces Are Required

A Linux VLAN interface such as:

1

vmbr0.25

is required when the Proxmox host itself needs an IP address on that VLAN.

For example:

1

vmbr0.25 → Proxmox management

Additional Linux VLAN interfaces are not required purely because VMs use those VLANs.

For example, these are unnecessary unless the Proxmox host itself needs connectivity on them:

1
2
3
4

vmbr0.10
vmbr0.20
vmbr0.30
vmbr0.40

11. Verify Management Networking

Check the management interface:

1

ip addr show vmbr0.25

Expected:

1

inet 10.10.11.10/24

Check vmbr0:

1

ip addr show vmbr0

It should not have the management IPv4 address assigned directly to it.

Check the routing table:

1

ip route

Expected default route:

1

default via 10.10.11.1 dev vmbr0.25

Test the gateway:

1

ping 10.10.11.1

Test external IP connectivity:

1

ping 1.1.1.1

Test DNS:

1

ping google.com

12. Verify Bridge VLAN Configuration

Show VLANs configured on Linux bridges:

1

bridge vlan show

Show detailed information for the management VLAN interface:

1

ip -d link show vmbr0.25

Show current interface configuration:

1

ip addr

Show routes:

1

ip route

13. VLAN 0 Troubleshooting

VLAN ID 0 should not normally be configured as a usable VLAN.

An incorrect configuration can produce an error similar to:

1
2

warning: netlink: vmbr0: cannot remove bridge vlan 0:
Invalid VLAN start 0

Check for VLAN 0 configuration:

1
2

grep -RniE 'vlan0|tag[[:space:]]+0|bridge-vids.*0|bridge-pvid.*0' \
  /etc/network /etc/pve/sdn 2>/dev/null

Check bridge VLAN state:

1

bridge vlan show

The bridge VLAN range should normally be:

1

bridge-vids 2-4094

rather than:

1

bridge-vids 0-4094

For management VLAN 25, use:

1

vmbr0.25

14. Useful Proxmox Networking Commands

Show all interfaces:

1

ip addr

Show interface names:

1

ip link

Show routing table:

1

ip route

Show bridge VLAN configuration:

1

bridge vlan show

Show management VLAN interface:

1

ip -d link show vmbr0.25

Show Proxmox network configuration:

1

cat /etc/network/interfaces

Edit network configuration:

1

nano /etc/network/interfaces

Apply network configuration:

1

ifreload -a

Reboot if required:

1

reboot

Final Network Layout 

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20

                         Proxmox Host
                         10.10.11.10
                              |
                         vmbr0.25
                          VLAN 25
                              |
                           vmbr0
                     VLAN-aware bridge
                              |
            +-----------------+-----------------+
            |                 |                 |
        VM VLAN 10        VM VLAN 20        VM VLAN 30
            |                 |                 |
            +-----------------+-----------------+
                              |
                         Physical NIC
                              |
                         Switch Trunk
                              |
                   Router / Firewall / LAN

Key Points

  • vmbr0 is VLAN-aware.
  • vmbr0 itself has no management IPv4 address.
  • vmbr0.25 carries the Proxmox management IP.
  • VLAN 25 is tagged on the physical switch trunk.
  • VMs connect directly to vmbr0.
  • VM VLANs are configured using the VLAN tag on each VM NIC.
  • Separate Linux VLAN interfaces are unnecessary unless the Proxmox host itself requires an IP on that VLAN.
  • The physical switch port must allow all VLANs required by the host and VMs.
QEMU Guest Agent Install