This object identifies the RPL Neighbour port of the ring . Valid values for this object are '0', 'IfIndex of fsErpsRingPort1' and 'IfIndex of fsErpsRingPort2'. When a port is configured as a RPL Neighbour port, that node becomes RPL Neighbour for that ring. [Reference : Section 10.1 of ITU-T G.8032 Y.1344 (03/2010)] Value '0' indicates that none of the ring ports is a RPL Neighbour port and hence the node is not a RPL Neighbour. In an interconnected node of a sub-ring, the 'fsErpsRingPort1' alone can be chosen as an RPL Neighbour port when administrator decides to have the interconnected node as the RPL Neighbour of the sub-ring. Both the RPL owner and RPL Neighbor node cannot be enabled at the same Ethernet Ring Node. Administrator has to ensure that, only one node in a ring is configured as RPL Neighbour ,and the node is adjacent to the RPL .