KVM, Hetzner subnets and routing

Question

linux

Given:
- Routing server running KVM and 4 virtual machines under it.
- 2 /29 subnets (6 IPs in each, respectively).

At present 4 virtualka work in the first subnet.
Everything is set up simply:
On boot, a script is launched that does the following:
brctl addbr br0
ifconfig br0 176.9.xxx.62 netmask 255.255.255.248 up
route add -host 176.9.xxx.58 dev br0
route add -host 176.9.xxx.59 dev br0
route add -host 176.9.xxx.60 dev br0
route add -host 176.9.xxx.61 dev br0

In virtual machines, the adapter settings are bridged to br0. Inside setting ip 176.9.xxx.58 mask 255.255.255.248 gw 176.9.xxx.62. It was configured approximately according to this guide: wiki.hetzner.de/index.php/KVM(God bless Google Translate).
Everything works perfectly.

Now there is a need to add 3-4 more virtual machines, so a new subnet 176.9.xxx.200 /29 was purchased
It would seem that the algorithm is as follows: Add a new br1 (with IP 176.9.xxx.206), then make routes from IP 176.9. xxx.200 - 176.9.xxx.205 to br1, specify bridge interface - br1 when creating virtual machines.
Everything seems to be so, but ... It does not work. When setting such settings in the guest OS, eth0 is not raised. When installing the OS, it says “It is not possible to apply these settings”, if you try to set the settings in an already installed OS, then after rebooting the network itself does not rise to ifup eth0, it gives the mysterious “Failed to bring up eth0”.
At the same time, 176.9.xxx.206 (gateway br1) is completely kicked from the outside.

What could be the problem?

Answer 1

debian.pro/347
Not at all.