Add additional IP not work

[J-B]

Hello,

I want to add a private IP to my Promox Host. I have two other Proxmox servers where it worked without any problems.

The other two Proxmox servers are updated from Proxmox 6. This server (that no work) is a new installation directly on Proxmox7.

On the other server I added the IP as follows.

auto vmbr0:1
iface vmbr0:1 inet static
        address 10.10.10.101
        netmask 255.255.255.0
        broadcast 10.10.10.255

When I try the same on the server where it doesn't work, I get the following error message.

~# ifup vmbr0:1
error: main exception: cannot find interfaces: vmbr0:1

If I try this:

auto vmbr0
iface vmbr0 inet static
        address xxxxxxxx/28
        gateway xxxxxxx
        bridge-ports eno1
        bridge-stp off
        bridge-fd 0

iface vmbr0 inet static
        address 10.10.10.200
        netmask 255.255.255.0

if up vmbr0

I don't get an error message back. However, the IP is also not reachable.

Where it works, there's this routing table.

~# ip route
default via 5.xxx.xxx.241 dev vmbr0 onlink
5.xxx.xxx.240/28 dev vmbr0 proto kernel scope link src 5.xxx.xxx.254
10.10.10.0/24 dev vmbr0 proto kernel scope link src 10.10.10.101

On the not working Server:

# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         5.xxx.xxx.241      0.0.0.0         UG    0      0        0 vmbr0
5.xxx.xxx.240      0.0.0.0         255.255.255.240 U     0      0        0 vmbr0

The route to the private IP is missing.

If I set the IP Settings to:

iface vmbr0 inet static
        address 10.10.10.200/24
        netmask 255.255.255.0

The route is showing. But all connections to the VMs disconnect. The VMs are not reachable anymore.

It's maddening because it works on two servers and not on this one. It's the same data center as well as the same VLAN.

Anyone a idea?

 

[J-B]

The solution is to replace ifupdown2 with ifupdown. But I don't know why it doesn't work with ifupdown2.