Enabling bridged connections with a single network card with multiple IP addresses

Mike asked:

I have a server with one network card in it (eth1). My server is assigned 5 public IP addresses and it is currently configured like this (/etc/network/interfaces):

# The primary network interface
allow-hotplug eth1
iface eth1 inet static
    address xxx.yyy.zzz.130
    netmask 255.255.255.248
    network xxx.yyy.zzz.128
    broadcast xxx.yyy.zzz.135
    gateway xxx.yyy.zzz.129

iface eth1:0 inet static
    address xxx.yyy.zzz.131
    netmask 255.255.255.248

iface eth1:1 inet static
    address xxx.yyy.zzz.132
    netmask 255.255.255.248

iface eth1:2 inet static
    address xxx.yyy.zzz.133
    netmask 255.255.255.248

iface eth1:3 inet static
    address xxx.yyy.zzz.134
    netmask 255.255.255.248

This is working perfectly, however I wanted to add a KVM virtual machine with a bridged connection with the public IP xxx.yyy.zzz.131.

If I do this:

auto br0
iface br0 inet static
  bridge-ports eth1
  bridge_stp off
  bridge_fd 0
  bridge_maxwait 0
  address xxx.yyy.zzz.131
  netmask 255.255.255.248

Then only xxx.yyy.zzz.131 is accessible. None of the other IPs are.

If I change it to bridge-ports eth1:0 I get the error:

SIOCSIFFLAGS: Cannot assign requested address
RTNETLINK answers: File exists
Failed to bring up br0.

If I comment out the other sections about eth1:0, in addition to the above error, I also get Ignoring unknown interface eth1:0=eth10. at the beginning.

How do I add a bridged device if I only have one NIC and multiple IPs?

My answer:


You should only have the IP address for the host on the host bridge. The IP addresses for the guests should be assigned only in the guests.


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