End Host Mobility Use Cases for LISP
draft-hertoghs-lisp-mobility-use-cases-01

Abstract

This memo proposes use cases for LISP in the area of end Host mobility. The applicability of end host mobility can be found in data centers, where Virtual Machines (VM's) can be moved freely from one physical server onto another physical server, independent of location, without having to change the IP/MAC-addresses inside those VMs, nor impacting traffic flows to and from those VMs. Wireless end hosts are another area of applicability. Although this draft will not address wireless end host mobility, most of the same principles apply. Traditionally L2 extension technologies have been used to handle mobility events, but they could lead to suboptimal routing of traffic to and from the end host after the mobility event, as well as created big broadcast domains. This memo describes how LISP solves the traffic optimization issues caused by a mobility event of an end host like a Virtual Machine, as it decouples the identity of the end host from its location, such that traffic will always be forwarded to the correct location. More-over the LISP control plane can be leveraged to discover and distribute the reachability information of end hosts such that end to end broadcast domains, and their associated problems, are no longer needed. Various sub-use cases will be looked at in this draft, depending on whether mobility is achieved at L2 (using MAC-addresses as EID) or at L3 (using IP addresses as EIDs), and whether subnets are L2 extended across LISP sites or not. This memo also describes how to handle mobility in the case where the default gateway of the end host is not capable of performing the LISP map-and-encap function, while the LISP xTR function is located one or more L3 hops away from the default gateway.

Authors

Yves Hertoghs
Marc Binderberger

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)