LISP Component for Communication with Non-LISP Sites

D.

LISP (Locator/ID Separation Protocol) is a routing and addressing architecture that separates the device identity (ID) and its location (locator) in IP networking. It is used to overcome the limitations of the current Internet architecture, where IP addresses are used for both identification and location, which can cause scalability and mobility challenges.

To enable communication between a LISP site and a non-LISP site, a LISP component called the Proxy ITR (PITR) is required. The PITR acts as a translator between the LISP and non-LISP sites, allowing traffic to flow between the two domains.

Here's how the communication works:

• When a LISP site wants to communicate with a non-LISP site, the traffic is sent to the local ITR (Ingress Tunnel Router).
• The ITR checks its mapping database to determine whether the destination IP address belongs to a LISP site or a non-LISP site.
• If the destination IP address belongs to a non-LISP site, the ITR encapsulates the traffic in a LISP header and forwards it to the PITR.
• The PITR removes the LISP header and forwards the traffic to the destination non-LISP site.
• When traffic is sent from the non-LISP site to the LISP site, the PITR encapsulates the traffic in a LISP header and forwards it to the ITR.
• The ITR removes the LISP header and forwards the traffic to the destination LISP site.

The other LISP components mentioned in the answer options are as follows:

• ITR (Ingress Tunnel Router): This is the router at the edge of a LISP site that receives traffic from a non-LISP site and encapsulates it in a LISP header before forwarding it to the ETR (Egress Tunnel Router) at the other end of the LISP site.
• ETR (Egress Tunnel Router): This is the router at the edge of a LISP site that receives traffic from the ITR and decapsulates it to send to the destination device.
• Proxy ETR (PETR): This is used in LISP Multi-Homing, where a site has multiple ETRs. The PETR advertises the same mapping for a LISP site to external sites to provide redundancy and load balancing.