Which of the below characteristics of RPL is true?

Which of the below characteristics of RPL is true?
A . RPL is designed for lossy networks.
B . RPL is an IPv6 link-state routing protocol.
C . RPL can send only messages in secured mode.
D . RPL uses hello messages to send routing updates to its neighbors.

View Answer

Answer: A

Explanation:

From:

http://www.openmote.com/standards/ietf-rpl.html

http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/rpl/configuration/15-mt/rpl-15-mt-book.html

RPL is the IPv6 Routing Protocol for LLN (Low-Power and Lossy Networks) as defined in RFC6550. The Routing Protocol for Low Power and Lossy Networks feature implements RPL on Cisco IOS software.

RPL Routing Attributes (Metrics and Constraints)

RPL makes use of a wide set of routing attributes that can be used either as constraints or metrics as against IGPs such as IS-IS or OSPF. When used as a constraint, the routing attribute allows pruning the links and nodes from candidate paths that do not respect the constraint; when used as a metric the routing attribute is used to determine the least cost path. Additionally, routing metrics can either be used as aggregated (e.g. path cost equal to the sum of the link metrics) or recorded in which case metrics of all links along the path are recorded and announced along with the path by RPL. Recorded metrics are particularly useful when aggregating metrics implies loosing relevant information for path selection.

Metrics can also be local (exchanged between two neighbors) or global (propagated along the path as the path cost).RPL uses dynamic metrics, which implies the use of low pass filters to preserve routing stability, avoid temporary loops and bind control traffic by limiting the number of advertised RPL messages due to link metrics updates and consequently path cost that may have a global impact by recomputing the routing topology.

Link-state algorithms (also known as shortest path first algorithms) flood routing information to all nodes in the internetwork. Each router, however, sends only the portion of the routing table that describes the state of its own links. In link-state algorithms, each router builds a picture of the entire network in its routing tables. Distance vector algorithms (also known as Bellman-Ford algorithms) call for each router to send all or some portion of its routing table, but only to its neighbors. In essence, link-state algorithms send small updates everywhere, while distance vector algorithms send larger updates only to neighboring routers. Distance vector algorithms know only about their neighbors.

https://datatracker.ietf.org/doc/rfc6550/?include_text=1