bonding + vlan (without untagged address)

[sub at nryc.fr]

Hello,

I have a server with two network cards, each card is plugged on a switch 
that as a default (untagged) network + a number of VLANs (tagged).

I'd like to bond the two interfaces and configure an IP address *only* 
on a tagged network, not on the default one.

I tried to use "eth0", "eth1" and "bond0" as "dummy" interfaces with no 
IP configured and "bond0.<vlan_ID>" as the real interface.

These are my configuration files :

/etc/modprobe.d/bonding.conf:
=============================
alias bond0 bonding
options bond0 mode=1 miimon=100

/etc/sysconfig/network-scripts/ifcfg-eth0
=========================================
DEVICE="eth0"
ONBOOT="yes"
BOOTPROTO="none"
SLAVE="yes"
USERCTL="no"
MASTER="bond0"

("ifcfg-eth1", is the same as "ifcfg-eth0 except" for the "DEVICE")

/etc/sysconfig/network-scripts/ifcfg-bond0
==========================================
DEVICE="bond0"
BOOTPROTO="none"
ONBOOT="yes"
USERCTL="no"

/etc/sysconfig/network-scripts/ifcfg-bond0.<vlan_ID>
====================================================
DEVICE="bond0.<vlan_ID>"
BOOTPROTO="dhcp"
ONBOOT="yes"
VLAN="yes"
USERCTL="no"

When I boot the server, eth0 and eth1 aren't going up, bond0 exists but 
complains that eth0/eth1 are not present and bond.<vlan_ID> is not up.

If I connect to the server with a KVM console and manually start the 
remaining interfaces (ifup eth0 / ifup eth1 / ifup bond0.<vlan_ID>, it 
works!

If I configure a IP address for bond0, it also works at bootime, but I 
don't want to do that.

Do you have an idea why eth0 and eth1 are not going up when bond0 as not 
IP address? Again, it works if I manually start the interfaces.

I tried on Red Hat Enterprise Linux 5.6 and 6.0, both 64 bits edition.

Regards,

Nicolas