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<p>Hello Lexi,</p>
<p>On Sat, Feb 22, 2025 at 01:34:51PM +0000, Lexi Winter wrote:</p>
<blockquote>
<p>i have an OSPF ABR in area 0 and area 1. this router has a default
route via a non-OSPF interface (kernel route, imported into BIRD using
the ‘kernel’ protocol). i’d like to advertise this route into area 1,
but <em>not</em> into area 0.</p>
<p>how would i go about doing that?</p>
</blockquote>
<p>I would filter out the default route on all the area 0 routers.</p>
<blockquote>
<p>please feel free to let me know if this is a bad idea or if i’m using
OSPF wrong :-)</p>
</blockquote>
<p>Well, OSPF isn’t intended for filtering routes between areas this
way. Guessing from what you have written, it may make sense e.g. to run
one OSPF instance per area, assign each area a BGP private ASN and run
BGP between them.</p>
<p>Have a nice weekend!<br />
Maria</p>
<p>–<br />
Maria Matejka (she/her) | BIRD Team Leader | CZ.NIC, z.s.p.o.</p>
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