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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">Michael Gale [mailto:gale.michael@gmail.com] wrote:<br>
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<b><span style="color:#1F497D"><o:p></o:p></span></b></span></p>
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<p class="MsoNormal"><span style="color:#1F497D">></span>Does anyone know if the work for Neutron Service Chains supports environments built with Linux Bridge as the Neutron ML2<span style="color:#1F497D">
</span>driver?<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">I don’t think it’s possible. I’m not aware of any document that says Linux Bridge doesn’t support modifications to its forwarding tables, but I think that’s for
the same reason that it’s unlikely that a car’s owner’s manual is unlikely to mention that you can’t seal the doors and use it for deep sea exploration. It’s not at all a use case the designers expected.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Service chaining is all about manipulating the forwarding tables in order to override the normal “forward via most direct path to destination” behavior. It relies
on the dataplane having a standard, documented and designed/intended mechanism for manipulating the forwarding tables in arbitrary (or at least fairly flexible) ways. I don’t believe Linux Bridge was designed with any intention to allow external software to
manipulate its forwarding behavior on a per packet/per destination basis.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">OvS and several other dataplanes are explicitly designed with the expectation and interface for an external controller to manipulate the forwarding in rich and
flexible ways.<o:p></o:p></span></p>
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