Dear Curtis, In the above example, the 2-hop route can update the 1-hop route because the current OSPF thinks it newer (Sec 3.4.2, RFC 2740), if we simply treat anycast as unicast. Note that an anycast address can be on multiple locations. And I use the anycast route list to maintain this information.
Besides, you can look at Case 2 section 3.5.1 in my draft. There is only one route (e.g. the 1-hop route) for a anycast address maintained by the current OSPF. If the route is withdrawn due to some reason (e.g. server power off or network disconnection), the alternative route (e.g. the 2-hop one) will be rediscovered until the next LSA refreshment (Sec 12.4, RFC2328). Note that the default LSRefreshTime is 30 minutes. This is my key point. I think OSPF would define it clearly for anycast. Thanks a lot for your discussion. On 12/22/06, Curtis Villamizar <[EMAIL PROTECTED]> wrote:
In message <[EMAIL PROTECTED]> "Yue Wang" writes: > > Dear Acee and All, > > The last thing to raise your attention (see below). > > Thanks a lot for your advice and discussion. Look forward to the > future anycast standard in OSPFv3. The point of this exercise was initially to determine whether there was work group support form making draft-wang-aospf-00 a WG document. There does not seem to be support for this. <big snip> > Note that anycast routes are not necessarily equal cost. > Suppose there are 2 anycast routes coming into a OSPF network in > sequence: the first is 1 hop, the second is 2 hop. As a result, ONLY > the 2-hop route stays in the network, if we treat anycast as unicast. > > That's why I differentiate anycast from unicast. You seem to have repeated this characterization of how unicast works a few times now. Second route does not replace the first if the first is lower costs. IMHO You have not demonstrated and need to change OSPF to support anycast. Acee had pointed out how it is done today (in rare instances where it is done at all) and you have not convinced anyone in the WG that there is an advantage to you approach. More important you have not convinced anyone to support this draft as a WG item. Perhaps Acee has a tally. No amount of vigorous assertion on your part is going to change that. Since there are few people speaking out, none for, only a few against, maybe the question can be posed at the next WG meeting. OTOH If more people speak out against this as a WG item between now and then, the draft should be considered a dead item. Curtis
-- regards, wang yue _______________________________________________ OSPF mailing list [email protected] https://www1.ietf.org/mailman/listinfo/ospf
