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<div class="moz-cite-prefix">On 8/Jan/20 14:44,
<a class="moz-txt-link-abbreviated" href="mailto:adamv0025@netconsultings.com">adamv0025@netconsultings.com</a> wrote:<br>
<br>
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<p class="MsoNormal"><span lang="EN-US">Would like to gather
current views of a wider community on BGP Path Attribute
Filtering (discarding selected attributes in particular, not
treat as withdraw) as an addition to the long list of
standard conditioning tools like max as-path length limit,
limiting number of communities all the way to running iBGP
infrastructure to carry Internet prefixes separate to the
one carrying customers’ L3/L2VPN prefixes. <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">And I appreciate the
topic is somewhat contentious and there’s no simple yes or
no answer either.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">My view is that in a
stub AS there should be no harm in discarding unused BGP
path attributes,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">On transit AS-es I’d
expect two opposing views:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">One might be: “I have a
business to run and don’t care about some university
experiments, so unless any of my customers specifically asks
for some attribute I’ll drop all reserved, unassigned and
deprecated ones and might even drop some not widely used
ones just to be on the well-trodden bug free path”<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Other might be: “These
experimental work is of great value to the community and
there’s a process now to announce and manage these
experiments, what about net neutrality, and besides modern
BGP implementations should handle well formatted attributes
and if it’s not the case its good that these flaws are being
exposed and fixed.”<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Please let me know your
thoughts.</span></p>
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<br>
From our side, on peering links, re-write all MED to 0 and scrubs
all communities, and replace them with our own.<br>
<br>
On customer links, we re-write MED to 0. While we don't scrub our
customer's specific communities, we do ensure they cannot use our
own, unauthorized internal communities beyond what we've allowed
them to.<br>
<br>
Mark.<br>
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