[CentOS] dummy interface shenanigans - CentOS6

[Frank Even]

On Wed, May 27, 2015 at 2:21 PM,  <m.roth at 5-cent.us> wrote:
> Frank Even wrote:
>> On Wed, May 27, 2015 at 1:37 AM, Frank Even
>> <lists+centos.org at elitists.org> wrote:
>>> tl;dr - a renamed dummy interface is not persisting across reboots on
>>> Cent6.
>>>
>>> I have a situation where I need to rename a dummy interface on my
>>> system.
>>>
>>> I have a total of 3 dummy interfaces:
>>>
>>> dummy0
>>> dummy1
>>> adummy0
>>>
>>> I've been doing some puppet testing in a vbox VM to get this all
>>> sorted out to deploy to a group of boxes.  Every time I reboot my VM,
>>> it comes up WITHOUT adummy0, but I notice there is now an unconfigured
>>> dummy2.
>>>
>>> I've tried everything from adding aliases to
>>> /etc/modprobe.d/dummyopts.conf to renaming the interface via "ip" (ip
>>> link set dummy2 name adummy0).  This is all fine during use, even
>>> during a network restart.  But as soon as I restart the VM, it comes
>>> back up broken.
>>>
>>> I for the life of me have been unable to figure out why.  I could use
>>> some help in narrowing down why this won't persist across reboots.  I
>>> can write a startup script to deal with it, but it doesn't seem like a
>>> good solution.
>>>
>>
>> Anybody have any insights?
>
> What's in /etc/udev/rules.d/70-persistant-net.rules?
>

Nothing that seems to be related to the issue:

# PCI device 0x8086:0x100e (e1000) (custom name provided by external tool)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*",
ATTR{address}=="08:00:27:96:5d:9c", ATTR{type}=="1", KERNEL=="eth*",
NAME="eth0"

I'm beginning to wonder if there has been some different handling
introduced into the latest updates as I had this working just fine on
a physical box, but I just ran a "yum -y update" and am now running
into the same problems.

What I need to be able to do is source a default route off of an IP
attached to a dummy interface.  But, for that source route to work off
of the routes declared in route-bond0, the dummy interface that has
the address I need to source needs to be up prior to bond0.  In
picking apart how networking brings up devices, it appears that it
simply orders them alphabetically.  So I created a dummy interface
called "adummy0" and attached my IP to it and all was working well.
Now, upon a reboot after updating to latest, the system refuses no
matter how I create the interface (adding alias/modprobes to
/etc/modprobe.d/dummyopts.conf or creating via "ip link" commands) to
maintain my "adummy0" interface across reboots.