  The growth and evolution of Internet of Things (IoT) is now of paramount
importance for next-generation networks, including the upcoming 6G. In
particular, there is a set of constrained IoT nodes that comprise the Low-Power
and Lossy Networks (LLNs), which have very particular requirements. The current
standard for routing in those networks is RPL, which was defined less than a
decade ago and still needs improvements in terms of scalability or integration
with other networks. Many researchers currently need an implementation of RPL
to evaluate their works and, for that reason, among others, we implemented it
in the OMNeT++ simulator. The results of this implementation show that is an
easy way to check prototypes in their very initial develop phases, and its code
is publicly available for the research community.
