11:51 a.m.
Date: Thu, 18 Apr 2013 14:14:32 -0400
From: Laine Stump <laine(a)laine.org>
To: libvir-list(a)redhat.com
Subject: Re: [libvirt] [PATCHv2] Configure native vlan modes on Open
vSwitch ports
Message-ID: <51703808.2000504(a)laine.org>
Content-Type: text/plain; charset=ISO-8859-1
On 04/18/2013 01:44 PM, james robson wrote:
> Hello,
> Has any one been able to review this yet? I realise that the 'Since
> 1.0.3' in the doc page is now out of date, but is the code itself
> acceptable?
I was hoping that someone with more knowledge of Open vSwitch and/or
vlan tagging/trunking/native mode would repond to the message (Kyle?)
but there was silence instead...
>
>
> diff --git a/tests/networkxml2xmlin/openvswitch-net.xml
> b/tests/networkxml2xmlin/openvswitch-net.xml
> index a3d82b1..93c49d5 100644
> --- a/tests/networkxml2xmlin/openvswitch-net.xml
> +++ b/tests/networkxml2xmlin/openvswitch-net.xml
> @@ -21,4 +21,13 @@
> <parameters profileid='alice-profile'/>
> </virtualport>
> </portgroup>
> + <portgroup name='tagged'>
> + <vlan native_mode='tagged' native_tag='123'>
> + <tag id='555'/>
> + <tag id='444'/>
> + </vlan>
> + <virtualport>
> + <parameters profileid='tagged-profile'/>
> + </virtualport>
> + </portgroup>
As brought up again in a separate conversation today, we prefer to use
camelCase rather than underscored in attribute and element names. So, if
we were to use the layout you're proposing, the attributes should be
called "nativeMode" and "nativeTag".
However, I'm wondering if there might be a better way to structure it.
What about this?
<vlan trunk='yes'>
<tag id='123' native='tagged|untagged'/> (or whatever values
are
appropriate)
<tag id='555'/>
<tag id='444'/>
</vlan>
Do I understand correctly that native mode is telling what to do with
packets that come in untagged, and that (using your nomenclature
"native_mode='yes' native_tag='123'" means "when an
untagged packet come
in from this interface, it should be tagged as 123 before forwarding"?
That is correct, setting the native vlan changes how an untagged packet
is handled when it enters the port. The difference between the 'tagged'
and 'untagged' modes is in how packets on the native vlan are processed
before exiting the port.
And what happens when native_mode='yes' but there is no
native_tag?
In that case you configuration is invalid, and will get an error.
(that's what I was trying to describe with <tag
id='123'
native='untagged'/>, but I don't even know if that makes sense, because
I don't know exactly what is the native vlan tag and what is done with
it :-)
That arrangement would make sense, I chose the arrangement I did for two
main reasons. There can only be one native vlan on a port, making it an
attribute of the 'vlan' tag enforces this. Also, I wanted to keep the
validation and processing separate rather than add 'if native' branches
to the loops that operate on the vlan id list.
I can see the advantage of having a single setting to configure the
native vlan, rather than the two attributes I proposed. If the new
suggestion is preferred I can rework my patch to use that format.
Also, is it valid to have a native_mode/native_tag if
trunk='no'? (right
now trunk is automatically set to 'yes' if there is more than one vlan tag)
It isn't valid to have trunk='no' and the native settings. Therefore
"<vlan trunk='no' native_mode='tagged'
native_tag='123'>" will get an
error if you try to enter it.
If no "trunk" attribute is set explicitly then it will be set to 'yes'.
This means "<vlan native_mode='tagged' native_tag='123'>"
is equivalent
to "<vlan trunk='yes' native_mode='tagged'
native_tag='123'>".
> </network>
> diff --git a/tests/networkxml2xmlout/openvswitch-net.xml
> b/tests/networkxml2xmlout/openvswitch-net.xml
> index a3d82b1..ab3d797 100644
> --- a/tests/networkxml2xmlout/openvswitch-net.xml
> +++ b/tests/networkxml2xmlout/openvswitch-net.xml
> @@ -21,4 +21,13 @@
> <parameters profileid='alice-profile'/>
> </virtualport>
> </portgroup>
> + <portgroup name='tagged'>
> + <vlan trunk='yes' native_mode='tagged'
native_tag='123'>
> + <tag id='555'/>
> + <tag id='444'/>
> + </vlan>
> + <virtualport>
> + <parameters profileid='tagged-profile'/>
> + </virtualport>
> + </portgroup>
> </network>
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