"Juergen Arlt" <[email protected]> wrote on 28/07/2009 12:22:44: > > As I need to convince our development team - can you give me some more > background on this. They are advertising currently the associated > address for the link (that to me is the incorrect approach) which caused > some misbehavior in the network. > Thanks and regards > Juergen
Just find the discussion in the archive. It was quite clear what to do. Acee Lindem, chair of OSPF WG, clarified this and there was no room for other interpretations. If you read the OSPF spec there are lots of hints and the previous version of the OSPF spec was very clear too. Jocke > > -----Original Message----- > From: Joakim Tjernlund [mailto:[email protected]] > Sent: Dienstag, 28. Juli 2009 12:15 > To: Arlt, Juergen (GERST:476S) > Cc: [email protected] > Subject: Re: [OSPF] Question about Stub advertisement of a PtP link RFC > 2328 > > > > > I have a very specific problem on an unnumbered point to point link > for an > > IPsec tunnel. This link is associated to another IP interfaces address > on the > > device to borrow an IP (source) address for the packets. The link > itself (as > > being unnumbered has no IP subnet assigned). > > Which option of the following in "12.4.1.1. Describing point-to-point > > interfaces" would apply for the stub area advertisement? > > In addition, as long as the state of the > interface > > is "Point-to-Point" (and regardless of the > > neighboring router state), a Type 3 link (stub > > network) should be added. There are two forms that > > this stub link can take: > > Option 1 > > Assuming that the neighboring router's IP > > address is known, set the Link ID of the Type > 3 > > link to the neighbor's IP address, the Link > Data > > to the mask 0xffffffff (indicating a host > > route), and the cost to the interface's > > configured output cost.[15] > > Option 2 > > If a subnet has been assigned to the point-to- > > point link, set the Link ID of the Type 3 link > > to the subnet's IP address, the Link Data to > the > > subnet's mask, and the cost to the interface's > > configured output cost.[16] > > I would read that option 2 would not apply as the link is unnumbered > therefore > > no subnet has been assigned to that link (even though an associated > address is set). > > For my specific PtP case the neighbor address is known as the tunnel > endpoint > > is manually configured (though not in any local network) therefore I > can use > > this for the Stub entry. > > Is that reading correct? > > There was a discussion about this some months ago(started by me) on this > subject. > The short answer is that for unnumbered links you don't send Option 1 > nor Option 2. The > spec is a bit unclear but that is what the list concluded. > > > What if we are talking about a virtual link? > > Although a virtual link acts like an > > unnumbered point-to-point link, it does have an associated IP > > interface address. This address is used as the IP source in > > OSPF protocol packets it sends along the virtual link, and is > > set dynamically during the routing table build process. > > Is has no known neighbor router IP as it knows only the neighbor > routers > > router-ID (not IP) and it has no subnet assigned to the virtual link > (though > > an associated IP). How should the stub advertisement look like - which > of the > > options apply? > > Regards > > Juergen Arlt > > ------------------------------------------------- > > Juergen Arlt > > Nortel GmbH > > Senior Network Solutions Engineer > > Global Network Technical Support > > Mittlerer Pfad 26 > > 70499 Stuttgart > > Germany > > Tel: +49 (711) 1394361 > > ESN: 595 4361 > > Fax: +49 (711) 1394330 > > ------------------------------------------------- > > _______________________________________________ > > OSPF mailing list > > [email protected] > > https://www.ietf.org/mailman/listinfo/ospf > > > _______________________________________________ OSPF mailing list [email protected] https://www.ietf.org/mailman/listinfo/ospf
