[lxc-users] Help with Ubuntu Networking

[CDR]

Dear Fajar
Thanks for the link, and it has just proven to me that there is
something broken in Ubuntu.
This is contradictory
 ifconfig br21
br21      Link encap:Ethernet  HWaddr fe:32:4e:82:0d:be
          BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

ifdown br21 --force
ifup br21
Ignoring unknown interface br21=br21. ############**************

as you can see, the bridge does exist, brctl shows it. It seems to be up.
That contradicts what happens when I turn it down and up again.
At some point the state machine lost the inner consistency.

Yours
Federico

On Sat, May 10, 2014 at 12:33 AM, Fajar A. Nugraha <list at fajar.net> wrote:
> On Sat, May 10, 2014 at 11:15 AM, CDR <venefax at gmail.com> wrote:
>> This is not related directly to LXC, but I know that some people here
>> work for Canonical, and before I get back to Fedora, I need to ask a
>> question.
>> I already Googled it and believe me, nobody has an answer, all are
>> more questions than responses.
>>
>> I need to bring up 12 empty bridges, that is, bridges that have no
>> interface and no IP.
>
> You're not looking hard enough
> https://www.google.com/search?q=ubuntu+bridge+without+ip+address
> http://wiki.1tux.org/wiki/Ubuntu/Bridge
>
>> In "interfaces", I have something like this
>> auto br0
>> iface br0 inet manual
>> pre-up echo "Starting $IFACE"
>> pre-up ip addr flush dev $IFACE
>> pre-up ip link set $IFACE down
>> post-down ip link set $IFACE down
>>
>> How do I create the bridge?
>> in /etc/rc.local I execute brctl addbr br0
>>
>> There is nothing wrong with this , right?
>
> Yes, there is.
>
> On trusty the error message is clearer: Cannot find device "br0"
>
> Basically ubuntu does not know "br2" is a bridge. You need (at the
> very least) "bridge_ports none". My example if the wiki uses dummy
> interface for the bridge.
>
>
> Here's another example (again, on trusty):
>
> (snippet from /etc/network/interface)
> auto fancy-if-name
> iface fancy-if-name inet static
>         bridge_ports none
>         address 0.0.0.0
>         netmask 0.0.0.0
>
> # brctl show fancy-if-name
> bridge name bridge id STP enabled interfaces
> fancy-if-name 8000.000000000000 no
>
> # ifconfig fancy-if-name
> fancy-if-name Link encap:Ethernet  HWaddr 02:aa:fd:37:bb:a5
>           inet6 addr: fe80::aa:fdff:fe37:bba5/64 Scope:Link
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>           RX packets:0 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:23 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:0
>           RX bytes:0 (0.0 B)  TX bytes:3809 (3.8 KB)
>
>
>> note: I will allow access to the box anybody whose email says @canonical.
>
> While you are entitled to give access to whoever you want, that note
> in my oppinion is a very selfish one. You're basically saying:
> - you want support from someone in canonical
> - you don't want to pay for the support
> - you don't trust anyone else in the list
>
> The open source community (including lxc) does not only consist of
> paid developers that work in a company. More often, a quick and useful
> answer will come from a fellow user.
>
> --
> Fajar
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