Use Case For Lisp Extranets - Cisco Nexus 7000 Series Configuration Manual

Use Case for LISP Extranets

network elements. A network that uses LISP virtualization binds VRFs to instance IDs (IIDs) and these IIDs
are used to support traffic flow segmentation across the overlay network. LISP learned mappings are kept
within the same instance ID (IID) or VRF context and are not shared across IIDs or VRFs, which means that
a host/resource can only talk to hosts/resources in VRFs with same IID.
For more information on LISP Virtualization, see the
3 chapter.
With the LISP Extranets feature, users can specify policies that allows host and resources residing in one VRF
(IID) domain to communicate with hosts in a separate VRF (IID) domain.
With LISP Extranets policies are specified in the Mapping System and the xTRs (Ingress Tunnel Router +
Egress Tunnel Router) discover the leaked routes on demand, as part of the regular route discovery process.
The implementation of LISP Extranets on LISP includes the following features:
• A Map Server (MS) device running Cisco IOS XE Everest 16.9.1 release or later, where the user can
• A VRF with valid LISP instance-ID configuration that can be configured to handle leaked map-caches
Use Case for LISP Extranets
Figure 20: Cisco NX-OS LISP Extranets Topology
The above figure illustrates the use of LISP Extranet policies. In the figure, there is a LISP shared virtualization
environment where routers (xTR1 and xTR2) extend to two VRF domains (VRF1 and VRF 2) using LISP
virtualization over an overlay fabric. A third router, xTR3, provides access to a different VRF domain (VRF3).
Each VRF domain is given a unique instance-ID (IID) value. According to LISP virtualization, hosts in a IID
domain can access resources within their same IID domain. For example, host 10.1.1.1 can only communicate
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establish LISP Extranet policies.
in LISP. This support is automatically provided on LISP from Cisco NX-OS Release 8.3(1) and later.
Configuring Locator ID Separation Protocol, on page
Configuring LISP Extranets