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Hi Seunghwan,<br>
<br>
It might be your problem isn't BIRD but packet filter related.<br>
<br>
Please check the BFD packets are allowed in iptables c.q. netfilter
using the correct ports and/or addresses.<br>
<br>
A possible reason why it starts working after a manual protocol
restart is a ESTABLISHED, RELATED rule.<br>
<br>
References:<br>
<ul>
<li><a class="moz-txt-link-freetext" href="https://tools.ietf.org/html/rfc5881">https://tools.ietf.org/html/rfc5881</a> (Encapsulation, IANA
Considerations)<br>
</li>
<li><a class="moz-txt-link-freetext" href="https://tools.ietf.org/html/rfc5883">https://tools.ietf.org/html/rfc5883</a> (IANA Considerations)<br>
</li>
</ul>
<br>
K.<br>
<br>
<div class="moz-cite-prefix">On 16-07-2020 11:00, seunghwan hwang
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAEtHQBxjTHb93s1m57oTc9SuV=jd3oFHN_YT5puSFeG28oag4A@mail.gmail.com">
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<div dir="ltr">Hello.
<div>BFD is Not working normally.</div>
<div>My configuration is shown below.</div>
<div><br>
</div>
<div>OS: Ubuntu 18.04</div>
<div>Kernel: 4.15.0-54-generic</div>
<div>BIRD ver: 1.6.8</div>
<div>==================================</div>
<div>protocol bfd {<br>
multihop {<br>
min rx interval 300 ms;<br>
min tx interval 300 ms;<br>
multiplier 3;<br>
};<br>
}<br>
</div>
<div><br>
</div>
<div>protocol bgp as1 {<br>
import all;<br>
export all;<br>
<br>
local ~ as ~;<br>
neighbor ~ as ~; <br>
enable route refresh off;<br>
hold time 90;<br>
bfd on;<br>
}<br>
<br>
protocol bgp as2 {<br>
import all;<br>
export all;
<br>
<br>
local ~ as ~;<br>
neighbor ~ as ~; <br>
enable route refresh off;<br>
hold time 90;<br>
bfd on; <br>
}<br>
</div>
<div>================================== <br>
</div>
<div><br>
</div>
<div>After system reboot(# shutdown -r now), BGP neighbor is
established, But BFD sessions are stuck in 'INIT' status. And
BIRD does not send BFD packets.<br>
</div>
<div>BFD sessions have recovered after restart protocol bfd1(#
birdc restart bfd1).</div>
<div><br>
</div>
<div>Is it a normal situation?</div>
<div>I think BFD has to start the mechanism after BGP neighbor
is UP.</div>
<div>Is there any missing part of my configurations?<br>
</div>
<div>Please check it.</div>
<div><br>
</div>
<div>Regards</div>
</div>
</blockquote>
<br>
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