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<P>Ok,</P>
<P>On the off chance that it wasn't clear in my original post when I said
"contrary to the design of OSPF (or any link state</P>
<P>protocol)", I am NOT advocating anyone doing this. I am simply pointing out
that Cisco IOS provides a knob to do what he described.</P>
<P>- Wayne</P>
<P> </P></FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=AElliott@xo.com href="mailto:AElliott@xo.com">Elliott, Andrew</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=wg-jnpr-nsp@wgustavus.com
href="mailto:wg-jnpr-nsp@wgustavus.com">'Wayne (juniper nsp)'</A> ; <A
title=B.Buxton@Planettechnologies.nl
href="mailto:B.Buxton@Planettechnologies.nl">'Ben Buxton'</A> ; <A
title=ajay.bhardwaj@in.spectranet.com
href="mailto:ajay.bhardwaj@in.spectranet.com">'Ajay Bhardwaj'</A> ; <A
title=juniper-nsp@puck.nether.net
href="mailto:'juniper-nsp@puck.nether.net'">'juniper-nsp@puck.nether.net'</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, February 18, 2003 10:26
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> RE: [j-nsp] Filtering OSPF
routes</DIV>
<DIV><BR></DIV>
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<P><FONT size=2>Wayne, </FONT><BR><FONT size=2> </FONT> <BR><FONT
size=2>I have seen this in action, and it is ugly.</FONT> <BR><FONT
size=2> </FONT> <BR><FONT size=2>I recently had to work on a Cisco
network where all routers were in</FONT> <BR><FONT size=2>one of two areas,
and they were using the distribute-lists to only</FONT> <BR><FONT size=2>use
the 0/0 LSA. This created many routing loops, and I asked the</FONT>
<BR><FONT size=2>"designer" what they were thinking, and basically got the
cold</FONT> <BR><FONT size=2>shoulder. I couldn't understand why someone
would want to use OSPF</FONT> <BR><FONT size=2>and then deliberately break it
in that manner.</FONT> <BR><FONT size=2> </FONT> <BR><FONT size=2>Has
anyone on this list ever seen a good reason to filter LSAs?</FONT> <BR><FONT
size=2> </FONT> <BR><FONT size=2>- -andrew</FONT> </P>
<P><FONT size=2>- -----Original Message-----</FONT> <BR><FONT size=2>From:
Wayne (juniper nsp) [<A
href="mailto:wg-jnpr-nsp@wgustavus.com">mailto:wg-jnpr-nsp@wgustavus.com</A>]
</FONT><BR><FONT size=2>Sent: Saturday, February 15, 2003 11:43 PM</FONT>
<BR><FONT size=2>To: Ben Buxton; Ajay Bhardwaj;
juniper-nsp@puck.nether.net</FONT> <BR><FONT size=2>Subject: Re: [j-nsp]
Filtering OSPF routes</FONT> </P><BR><BR>
<P><FONT size=2>Actually, if you are running a sufficiently high enough
version of</FONT> <BR><FONT size=2>IOS (e.g. 12.0S), the 7200 can filter some
LSAs. It depends on your</FONT> <BR><FONT size=2>exact scenario if this
will accomplish what you are trying to do. It</FONT> <BR><FONT
size=2>does tend to go contrary to the design of OSPF (or any link
state</FONT> <BR><FONT size=2>protocol), but I suppose enough people wanted
the knob, so they got</FONT> <BR><FONT size=2>it.</FONT> <BR><FONT
size=2> </FONT> <BR><FONT size=2>Not sure if JUNOS has a similar
knob.</FONT> <BR><FONT size=2> </FONT> <BR><FONT size=2>- - Wayne
</FONT></P>
<P><FONT size=2>- ----- Original Message ----- </FONT><BR><FONT size=2>From:
Ben Buxton </FONT><BR><FONT size=2>To: Ajay Bhardwaj ;
juniper-nsp@puck.nether.net </FONT><BR><FONT size=2>Sent: Monday, February 10,
2003 4:18 AM</FONT> <BR><FONT size=2>Subject: RE: [j-nsp] Filtering OSPF
routes</FONT> </P>
<P><FONT size=2></FONT> <BR><FONT size=2>You cannot filter OSPF. This would
break the requirement that all</FONT> <BR><FONT size=2>routers have</FONT>
<BR><FONT size=2>the same link state view.</FONT> <BR><FONT size=2>This is
true for both Junos and IOS.</FONT> <BR><FONT size=2> </FONT> <BR><FONT
size=2>BB</FONT> </P>
<P><FONT size=2>- -----Original Message-----</FONT> <BR><FONT size=2>From:
Ajay Bhardwaj [<A
href="mailto:ajay.bhardwaj@in.spectranet.com">mailto:ajay.bhardwaj@in.spectranet.com</A>]
</FONT><BR><FONT size=2>Sent: Monday, 10 February 2003 08:39</FONT> <BR><FONT
size=2>To: juniper-nsp@puck.nether.net</FONT> <BR><FONT size=2>Subject:
[j-nsp] Filtering OSPF routes</FONT> </P><BR>
<P><FONT size=2>Hi all,</FONT> <BR><FONT size=2> </FONT> <BR><FONT
size=2>We have cisco 7200 router and M-5 router both running ospf and
part</FONT> <BR><FONT size=2>of area 10.</FONT> <BR><FONT size=2> </FONT>
<BR><FONT size=2>I want to deny few routes which are flowing trough ospf from
7200 to</FONT> <BR><FONT size=2>m5 either at 7200 side or m5 side. Pls if
anyone have any solution to</FONT> <BR><FONT size=2>this would be gr8 help for
me.</FONT> <BR><FONT size=2> </FONT> <BR><FONT size=2>Ajay
Bhardwaj</FONT> </P><BR><BR>
<P><FONT size=2> _____ </FONT></P><BR><BR><BR>
<P><FONT size=2>_______________________________________________</FONT>
<BR><FONT size=2>juniper-nsp mailing list juniper-nsp@puck.nether.net</FONT>
<BR><FONT size=2><A href="http://puck.nether.net/mailman/listinfo/juniper-nsp"
target=_blank>http://puck.nether.net/mailman/listinfo/juniper-nsp</A></FONT>
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