proxmox and 2 vm with outer ip: and different gw

[koskelainen]

Server at hetzner, and there is 2 vm servers, one is workign fine, one cant even ping anything
One problem is that there is 2 gateways, as Hetzner gives random ip addresses and gw (ip with mac )
proxmox machines settings:
source /etc/network/interfaces.d/*

auto lo
iface lo inet loopback

iface lo inet6 loopback

auto enp6s0
iface enp6s0 inet manual


auto vmbr1
iface vmbr1 inet static
address 95.z.142/26
bridge-ports none
bridge-stp off
bridge-fd 0

auto vmbr0
iface vmbr0 inet static
address 95.z.186/26
gateway 95.z.129
bridge-ports enp6s0
bridge-stp off
bridge-fd 0
#c

iface vmbr0 inet6 static
address 2a01:z:3583::2/64
gateway fe80::1

auto vmbr3
iface vmbr3 inet static
address 65.z.62/26
bridge-ports none
bridge-stp off
bridge-fd 0

GW for vmbr3 address is x.49 ending


Non working vm has ip and gw set on neplan, yes proxmox machine has interfaces and vm have netplan settings
When ssh to ip of non work vm, it directs to proxmox machine ip
I have tried with gpt help but quite hard do work on proxmox console without copy-paste
As i have very little knowledge of linux networking

 

[readyspace]

Hi, you’re likely hitting a routing and proxy ARP issue caused by multiple gateways and Hetzner’s MAC-bound IP setup.

At Hetzner, each additional IP or subnet must be assigned to a unique virtual MAC and attached to the VM NIC — you can’t just add a second gateway or subnet to the Proxmox host. The VM must route traffic via its own gateway (with the matching MAC) instead of sharing the host’s.

Some direction for you:

• Keep only one default gateway on the Proxmox host.
• Assign each VM its own vMAC in the Hetzner Robot/Cloud console.
• Map that vMAC to the VM’s NIC using “virtio-macaddr” in the VM config.
• Don’t bridge multiple public subnets on the same vmbr.

I found some places where you can do more research on what you want to achieve here

• Hetzner official doc: https://docs.hetzner.com/robot/dedicated-server/network/additional-ips/
• Proxmox networking: https://pve.proxmox.com/pve-docs/pve-admin-guide.html#sysadmin_network_configuration
• Forum example: https://forum.proxmox.com/threads/networking-on-hetzner.34356/

Use one host gateway, per-VM vMACs, and static routes — not multiple gateways on Proxmox.

 

[HOSTWAY IDC]

Hi. Which vmbr are the two VM servers connected to?
It seems there is a possibility that communication may not work depending on the bridge, VLAN, and vmbr bridge port configuration.