Re: Configuring multiple IP addresses on VLAN interface using ifupdown

[Tom H <tomh0665@gmail.com>]

On Fri, Oct 18, 2013 at 12:05 PM, Steffen Dettmer
<steffen.dettmer@gmail.com> wrote:
> On Fri, Oct 18, 2013 at 1:18 PM, Tom H <tomh0665@gmail.com> wrote:


> thanks again for your fast help.

You're welcome.


>> So Bob must be right about your ifupdown version not using iproute
>
> I'm using Wheezy with ifup version 0.7.8, I think this is the
> latest officially released (aka "the best") one?

Strange. I was under the impression that Debian 7's ifupdown is using
iproute but you had a vconfig error in an earlier email - and the
"trying to add" error below also looks like an ioctl error rather than
a netlink one.


>> and, as he suggested, you're going to have to use the equivalent of:
>>
>> allow-auto eth0.9
>> iface eth0.9 inet static
>> address 192.168.1.119
>> netmask 255.255.255.0
>> gateway 192.168.1.1
>> post-up ip address add 192.168.1.199/24 dev eth0.9
>
> I took this 1:1 resulting in the following /etc/network/interfaces file:
>
> ------------------------------------------------------------------->8=======
> auto lo
> iface lo inet loopback
>
> allow-auto eth0.9
> iface eth0.9 inet static
>   address 192.168.1.119
>   netmask 255.255.255.0
>   gateway 192.168.1.1
>   post-up ip address add 192.168.1.199/24 dev eth0.9
> =======8<-------------------------------------------------------------------
>
> Now I get "ERROR: trying to add VLAN #9 to IF -:eth0-  error: File exists"
> "only" once, but still.

Does anyone know whether adding an ip address with ip to an interface
configured with ifconfig isn't possible? Probably not.

So the post-up should be "post-up ifconfig eth0.9:0 192.168.1.199
netmask 255.255.255.0 up", although I can't remember ever coming
across such an interface (or know whether it's possible to do
something like this with net-tools!).

Maybe you could try to do what you want using net-tools manually to
remove any ifupdown bug from the mix.

You'd need to take down your network and only have "lo" defined in
"/etc/network/interfaces" (or reboot with just "lo" defined). Then

ifconfig eth0 0.0.0.0 netmask 255.255.255.255 up
vconfig set_name_type DEV_PLUS_VID_NO_PAD
vconfig add eth0 9
ifconfig eth0.9 192.168.1.119 netmask 255.255.255.0 up
ifconfig eth0.9:0 192.168.1.199 netmask 255.255.255.0 up

to bring them up

and

ifconfig eth0.9:0 down
ifconfig eth0.9 down
vconfig rem eth0.9
ifconfig eth0 down

to take them down.

You could try to do the same with iproute but your system seems to be
a net-tools one, weirdly.


> Is the example above correct? Does it work for you? Could your
> machine be boot so quickly that it might not be visible without
> adding --noclear to /etc/inittab for tty1 getty?

I tested once. I just took down the network so that only "lo" was
defined and then brought it up with what I'd posted.