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<div class="moz-cite-prefix">On 01/08/2020 00:50, Mark Tinka wrote:<br>
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<blockquote type="cite"
cite="mid:aeceb486-57f2-a23b-bbe3-df47c5e4f085@seacom.com">
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On 31/Jul/20 23:38, Sabri Berisha wrote:
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<pre class="moz-quote-pre" wrap="">Kudos to Telia for admitting their mistakes, and fixing their processes.
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Considering Telia's scope and "experience", that is one thing. But for
the general good of the Internet, the number of intended or
unintentional route hijacks in recent years, and all the noise that
rises on this and other lists each time we have such incidents (this
won't be the last), Telia should not have waited to be called out in
order to get this fixed.
Do we know if they are fixing this on just this customer of theirs, or
all their customers? I know this has been their filtering policy with us
(SEACOM) since 2014, as I pointed out earlier today. There has not been
a shortage of similar incidents between now and then, where the
community has consistently called for more deliberate and effective
route filtering across inter-AS arrangements.
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<p>AS level filtering is easy. IP prefix level filtering is hard.
Especially when you are in the top 200:</p>
<p><a class="moz-txt-link-freetext" href="https://asrank.caida.org/">https://asrank.caida.org/</a></p>
<p><br>
</p>
<p>That being said, and due to these BGP "polluters" constantly
doing the same thing, wouldn't an easy fix be to use the
max-prefix/prefix-limit option:</p>
<p><a class="moz-txt-link-freetext" href="https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/25160-bgp-maximum-prefix.html">https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/25160-bgp-maximum-prefix.html</a></p>
<p><a class="moz-txt-link-freetext" href="https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/prefix-limit-edit-protocols-bgp.html">https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/prefix-limit-edit-protocols-bgp.html</a></p>
<p><br>
</p>
<p>For every BGP peer, the ISP determines what the current
max-prefix currently is. Then add in 2% and set the max-prefix.
</p>
<p>An errant BGP polluter would then only have limited damage to the
Internet routing table.</p>
<p>Not the greatest solution, but easy to implement via a one line
change on every BGP peer.</p>
<p><br>
</p>
<p>Smaller ISPs can easily do it on their 10 BGP peers so as to
limit damage as to what they will hear from their neighbors.<br>
</p>
<p><br>
</p>
<p>-Hank</p>
<p><br>
</p>
<p>Caveat: The views expressed above are solely my own and do not
express the views or opinions of my employer <br>
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