Hello,
I'm trying to set up IP aliases within a QEMU/KVM guest on CentOS 5.5 x86_64, going through a bridged virtualized interface.
The virtualized interface in the guest is configured as follow:
# ifcfg-eth1
DEVICE=eth1 BOOTPROTO=none PEERDNS=yes GATEWAY=IP.OF.HOST.GATEWAY HWADDR=11:11:11:11:11:11 IPADDR=IP.OF.GUEST.ETH1 NETMASK=255.255.255.255 ONBOOT=yes ARP=yes USERCTL=no IPV6INIT=no
# route-eth1
IP.OF.HOST.GATEWAY dev eth1 default via IP.OF.HOST.GATEWAY dev eth1
This is the configuration recommended by the provider (OVH) after a virtual MAC address has been allocated for IP.OF.GUEST.ETH1: http://help.ovh.com/BridgeClient
It works fine for virtual interfaces added via libvirt/QEMU.
But when I try to configure an IP alias on another IP address aliasing a virtualized interface, as per the instructions from http://help.ovh.co.uk/IpAlias (and after assigning it a virtual mac just like for eth1) :
# ifcfg-eth1:1
DEVICE=eth1:1 BOOTPROTO=none PEERDNS=yes GATEWAY=IP.OF.HOST.GATEWAY HWADDR=22:22:22:22:22:22 IPADDR=IP.OF.GUEST.ETH1:1 NETMASK=255.255.255.255 ONBOOT=yes ARP=yes USERCTL=no IPV6INIT=no
I get the following error when restarting the network:
SIOCADDRT: Network is unreachable
and IP.OF.GUEST.ETH1:1 is: - pingable from the same guest - not pingable from other guests by the same provider - not pingable from outside
Setting BOOTPROTO=static or commenting out #GATEWAY=IP.OF.HOST.GATEWAY or setting: NETMASK=255.255.255.252 (the IP block was a /30, but I don't think that has something to do here)
did not change the behavior.
I'll be interested to hear from experiences with setting IP alias from within a guest. Maybe my problem is due to the configuration of the provider network and it is actually impossible to use IP aliases on virtualized interfaces. Any opinion/idea welcome!
Mathieu