Multi-homing (RBridge Aggregation) is a promising approach to
increase the reliability and access bandwidth of TRILL edge. Active-
active forwarding in multi-homing allows multiple RBridges forward
data frames for VLAN-x on a LAN link, which creates the possibility
that multicast frames from a specific ingress RBridge may arrive at
multiple incoming ports of a remote RBridge. This violates the
Reverse Path Forwarding Check and multicast frames arrives at
unexpected incoming ports will be discarded by this RBridge. This
document makes use of multiple topology TRILL to solve this problem.
Multiple topology TRILL provides physical separation of traffic from
different members of aggregation. Multicast frames from aggregation
members comply with the Reverse Path Forwarding Check per topology.