<html>
<head>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
<p>Hi,</p>
<p>this would brake OSPF completely. You can only filter routes
between area's and not within. This is fundamental for link state
protocols like OSPF</p>
<p><br>
</p>
<p>Eelco Nieuwstad<br>
</p>
<br>
<div class="moz-cite-prefix">On 27-01-17 08:53, Steve Leung wrote:<br>
</div>
<blockquote
cite="mid:CAFr5Kh4KWE36zP2SjVVCY4=tALL6naptxs5RW+=ZAv9jzYfbDw@mail.gmail.com"
type="cite">
<div dir="ltr">Hi,
<div><br>
</div>
<div>Using OSPF, when receiving some routes from a network
interface, by default all routes will be re-advertised to
other interfaces within the same area without applying the
filter rules.<br clear="all">
<div>
<div class="gmail_signature">
<div dir="ltr">
<div dir="ltr"><br>
</div>
<div dir="ltr">Say in the below example.<br>
</div>
<div dir="ltr"><br>
</div>
<div dir="ltr">===</div>
<div dir="ltr">
<div dir="ltr">protocol ospf myospf {</div>
<div dir="ltr"> table t_ospf;</div>
<div dir="ltr"> import filter ifilter;</div>
<div dir="ltr"> export filter ofilter;</div>
<div dir="ltr"> area 0 {</div>
<div dir="ltr"> interface "eth*" {</div>
<div dir="ltr"> hello 10;
retransmit 2; wait 10; dead 300; cost 10;</div>
<div dir="ltr"> };</div>
<div dir="ltr"> };</div>
<div dir="ltr">}</div>
<div dir="ltr">===</div>
<div dir="ltr"><br>
</div>
<div>Routes received from "eth1" will be _forwarded_
to "eth2" and bypassed all the filters. Is it
possible to configure bird.conf so only some of the
routes will be re-advertised? (aka apply filters to
interface within the same OSPF area)</div>
<div><br>
</div>
<div>Creating multiple ospf instance and treat the
routes as "external routes" (so filter will apply)
is not a good idea for me because the environment is
quite dynamic, may even have hundreds of dynamic
virtual interface, and I hope I do not need to edit
the config file all the time.</div>
<div><br>
</div>
<div>Thank you so much for your time.</div>
<div><br>
</div>
</div>
<div dir="ltr"><br>
Best regards,<br>
Steve<br>
<div>
<p><br>
</p>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</blockquote>
<br>
</body>
</html>