The key is hidden in this sentence: This > also means that the network path betwen host -> border has to do some > internal TE such that when on exit path is 'bad' traffic naturally flows > toward an alternate path internally toward a 'better' exit path.
If the path really doesn't work at all, yes, site TE should make sure things go to the working exit. But if ILNP wants some destiantiosn to be reached using exit 1, and some reached using exit 2, most sites simply do not have any practical way to do that. And if you want the hosts to decide for itself whether it shoudl use exit 1 or exit 2 to reach rloc 1, rloc2, or rloc 3, then site TE can not solve the problem. So currently, it does not work very well. And there are cases that we would liek to work that simply don't. (I believe shim6 ran into very similar issues, and decided to not address them for now.) Yours, Joel On Sat, June 5, 2010 2:32 pm, Christopher Morrow wrote: > On Thu, Jun 3, 2010 at 5:44 PM, Joel M. Halpern <[email protected]> > wrote: > >> I believe that Patrick is asking about outbound traffic routing, not >> inbound. >> >> Which is very reasonable question to ask. >> >> >> Unfortunately, until we are prepared to make a much larger set of >> changes, we do not have the tools to allow a host to choose which >> outbound site connection is used by the hosts outbound traffic. (There >> are many use cases which would like those capabilities, but we have not >> found a good way to deliver them.) > > I was under the impression that ILNP would permit the site border > routers to change the locator bits on exit. This means the network devices > and the hosts have to agree on the set of locators they all can use. This > also means that the network path betwen host -> border has to do some > internal TE such that when on exit path is 'bad' traffic naturally flows > toward an alternate path internally toward a 'better' exit path. > > > If the above all works, then the borders simple swap locator bits as > appropriate on exit... easy, peasy. > > -chris > > >> yours, Joel >> >> >> Tony Li wrote: >> >>> >>> >>> On 6/4/10 5:21 AM, "Patrick Frejborg" <[email protected]> wrote: >>> >>> >>>> A question regarding ILNP and multi-homing scenario. >>>> The primary path from A towards Internet goes via attachment point B >>>> and this is announced in DNS. Then ISP taking care of attachment >>>> point B have some performance problems and the service is not good >>>> enough for host A - he decides to switch to attachment point C and >>>> updates DNS. But how does the packet get routed from host A to >>>> attachment point C instead of B in large enterprise network where >>>> there could be a lot of routers and some security nodes between the >>>> host and the attachment points? I don't want to tweak the local >>>> routing domain but when I change the DNS records host A should start >>>> to use new attachment point (C), some other hosts might still use >>>> the old one (B). >>> >>> >>> In ILNP, a host controls how packets arrive by changing the locators >>> that are advertised. Outbound, intra-domain packet routing is >>> separate, and COULD be based on the hosts source locator, but this is >>> a separate enhancement that we could make. >>> >>> Once the host updates DNS with the C locator, it should also >>> concurrently send ICMP locator updates to its active correspondents >>> and inform them of the C locator. Tony >>> >>> >>> >>> _______________________________________________ >>> rrg mailing list [email protected] http://www.irtf.org/mailman/listinfo/rrg >>> >>> >> _______________________________________________ >> rrg mailing list [email protected] http://www.irtf.org/mailman/listinfo/rrg >> _______________________________________________ rrg mailing list [email protected] http://www.irtf.org/mailman/listinfo/rrg
