  Trends like Industry 4.0 will pose new challenges for future industrial
networks. Greater interconnectedness, higher data volumes as well as new
requirements for speeds as well as security will make new approaches necessary.
Performanceoptimized networking techniques will be demanded to implement new
use cases, like network separation and isolation, in a secure fashion. A new
and highly efficient protocol, that will be vital for that purpose, is MACsec.
It is a Layer 2 encryption protocol that was previously extended specifically
for industrial environments. Yet, it lacks the ability to bridge local
networks. Therefore, in this work, we propose a secure and efficient Layer 3
tunneling scheme for MACsec. We design and implement two approaches, that are
equally secure and considerably outperform comparable state-of-the-art
techniques.
