> > On Thu, Jul 17, 2014 at 10:03 PM, Dino Farinacci <[email protected]> wrote: > > 2) Is my understanding correct that all EIDs within a site would be mapped > > to a single RLOC as a result of query to the map server? > > Yes, if all those EIDs are in the same power-of-2 prefix which is registered > to the mapping system as an EID-prefix. > > By mapping, I'd mean mapping an EID to a RLOC so that the remote node would > know which RLOC should be used to reach a LISP site where the node of the > very EID belongs. I don't think this mapping has anything to do with an > EID-prefix. Am I mistaken?
Say you have a cluster of VMs that work together at the applicaiton-layer. And you want to move them together to a cloud provider. In this case the EIDs of the VMs in the cluster are part of the same power-of-2 prefix. In this case, that is an EID-prefix that moves so the new set of RLOCs are the one that reside at the cloud provider. > Another related question might be.... is there any compelling reason why EIDs > within a site should better be assigned in the same power-of-2 prefix? If they fate-share RLOC changes, they should be assigned in power-of-2 blocks. > If the EID would be assigned to a node, it wouldn't matter much. Or is it to > save entry space in the mapping server? The only real issue with assigning addresses to nodes versus interfaces (this is a general comment), is if the routers know directly how to reach the address. When the address is assigned to an interface, routers are directly attached to the subnet of node's interface address. When it is assigned say to a loopback interface, the routers need more information to know what physical interface the node is reachable on. This discussion happened in the 80s when designing DECnet and the OSI network layer. And the discussion came up again for IPng. As you know by now, IPv6 has interface assigned addresses much like IPv4. > The power-of-2 might make sense if the EID is, in fact, assigned to the > interface just like the Internet. Then, you would benefit from more efficient > interior routing by subnet masks. > > Where am I lost? I don't think you are. You just want to get a deeper understanding, which is great! Dino > > > > > -- > DY _______________________________________________ lisp mailing list [email protected] https://www.ietf.org/mailman/listinfo/lisp
