<div dir="ltr"><div dir="ltr"><div class="gmail_default" style="font-family:monospace,monospace">Hi Cody,</div><div class="gmail_default" style="font-family:monospace,monospace"><br></div><div class="gmail_default" style="font-family:monospace,monospace">Firstly, I don't work for the Openstack team. I'm with Red Hat Openshift, but I've worked with Openstack in the past and still have an interest in it and follow some of the mailing lists.</div><div class="gmail_default" style="font-family:monospace,monospace"><br></div><div class="gmail_default" style="font-family:monospace,monospace">From past experience, and from what I take from the docs you linked is:</div><div class="gmail_default" style="font-family:monospace,monospace"><br></div><div class="gmail_default" style="font-family:monospace,monospace"><br></div><div class="gmail_default" style="font-family:monospace,monospace">Older versions of Openstack have the integration bridge (br-int) which routes traffic to the external bridge (br-ex) and traffic then flows through the physical interface.</div><div class="gmail_default" style="font-family:monospace,monospace">But this limits you to a single floating IP range.</div><div class="gmail_default" style="font-family:monospace,monospace"><br></div><div class="gmail_default" style="font-family:monospace,monospace"><br></div><div class="gmail_default" style="font-family:monospace,monospace">So, newer versions of Openstack set the external bridge setting as empty by default ( NeutronExternalNetworkBridge: "''" ).</div><div class="gmail_default" style="font-family:monospace,monospace">This allows you the capability of mapping multiple physical interfaces (bonded interfaces or trunked vlans) directly. While this method removes the ex-br, you are still introducing an overhead as you are routing multiple networks over one or more physical interfaces - hence the additional CPU usage.</div><div class="gmail_default" style="font-family:monospace,monospace"><br></div><div class="gmail_default" style="font-family:monospace,monospace">What the docs are saying is, if you intend to use multiple external networks (multiple floating IP rages) then leave this empty (as by default):</div><div class="gmail_default" style="font-family:monospace,monospace"><br></div><div class="gmail_default" style="font-family:monospace,monospace"><span style="font-size:small;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">NeutronExternalNetworkBridge: "''"</span><br></div><div class="gmail_default" style="font-family:monospace,monospace"><span style="font-size:small;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline"><br></span></div><div class="gmail_default" style="font-family:monospace,monospace"><span style="font-size:small;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">But if you are only intending to use one external network (one floating IP range), then revert back to the old way of mapping the network to br-ex - otherwise, you are introducing an additional unnecessary overhead that you are not making use of.</span></div><div class="gmail_default" style="font-family:monospace,monospace"><span style="font-size:small;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline"><br></span></div><div class="gmail_default" style="font-family:monospace,monospace">hope this helps.</div><div class="gmail_default" style="font-family:monospace,monospace"><br></div><div class="gmail_default" style="font-family:monospace,monospace">kind regards,</div><div class="gmail_default" style="font-family:monospace,monospace"><br></div></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Sep 19, 2018 at 6:13 PM, Cody <span dir="ltr"><<a href="mailto:codeology.lab@gmail.com" target="_blank">codeology.lab@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi there,<br>
<br>
I sent a similar question below to OpenStack ML last week, but haven't<br>
got any answers yet. Since it is a TripleO related question, I am<br>
reposting it here and hope for a better luck.<br>
<br>
According to the TripleO documentation [1], the default Neutron<br>
external bridge (NeutronExternalNetworkBridge) is left empty. This<br>
seems to let the physical interface map to br-int instead of br-ex,<br>
and (somehow) use more CPU power as oppose to using br-ex directly. I<br>
don't get it... Does it mean the external traffic would go directly<br>
from br-int to the physical interface without using br-ex? Could<br>
someone walk me through the traffic flow in this case? I really<br>
appreciate your help!<br>
<br>
[1] <a href="https://docs.openstack.org/tripleo-docs/latest/install/advanced_deployment/network_isolation.html#using-the-native-vlan-for-floating-ips" rel="noreferrer" target="_blank">https://docs.openstack.org/<wbr>tripleo-docs/latest/install/<wbr>advanced_deployment/network_<wbr>isolation.html#using-the-<wbr>native-vlan-for-floating-ips</a><br>
<br>
<br>
Regards,<br>
Cody<br>
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</blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div><font face="arial, helvetica, sans-serif">Paul Yates</font></div><div><font face="arial, helvetica, sans-serif">Red Hat,<br></font></div><div><div style="font-size:12.8px"><font face="arial, helvetica, sans-serif">Communications House,</font></div><div style="font-size:12.8px"><font face="arial, helvetica, sans-serif">Cork Road,</font></div></div><div><font face="arial, helvetica, sans-serif">Waterford, </font></div><div><font face="arial, helvetica, sans-serif">I<span style="font-size:12.8px">reland. </span></font></div><div><font face="arial, helvetica, sans-serif">phone: <a href="tel:%2B420%20532294734" style="font-size:12.8px" target="_blank">+353 51 810166</a> </font></div><div><font face="arial, helvetica, sans-serif">Email: <a href="mailto:lsvobodo@redhat.com" style="font-size:12.8px" target="_blank">pyates@redhat.com</a></font></div><div><img src="cid:64436C8B-2113-4D1D-B00B-E76AD8BE10A1"><br><br></div>
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