<div dir="ltr">Yea I know this is not standard, but for some reason I need to figure out how to handle this scenario, you know sometimes we do not have control of the whole network :(   <div class="gmail_extra"><div><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div dir="ltr"><br>Best regards,<br>Steve</div><div dir="ltr"><br></div></div></div></div>
<br><div class="gmail_quote">2017-01-27 21:52 GMT+08:00 Eelco Nieuwstad <span dir="ltr"><<a href="mailto:eelco.nieuwstad@columbo.nl" target="_blank">eelco.nieuwstad@columbo.nl</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
  
    
  
  <div 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><span class="HOEnZb"><font color="#888888">
    <p><br>
    </p>
    <p>Eelco Nieuwstad<br>
    </p></font></span><div><div class="h5">
    <br>
    <div class="m_4149306641159932215moz-cite-prefix">On 27-01-17 08:53, Steve Leung wrote:<br>
    </div>
    <blockquote 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="m_4149306641159932215gmail_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>
  </div></div></div>

</blockquote></div><br></div></div>