a protocol identifies and configures rings in a network topology automatically in order to simplify and quicken the actions that need to be performed in response to addition , deletion and shuffle of network nodes in that topology . such rings do not need to be identified and configured manually . the protocol involves two separate sequentially performed phases . in the first phase , the protocol can automatically identify all rings that are present within a virtual local area network topology . in the second phase , the protocol can automatically configure each node of each such ring in conformity with the ethernet ring protection protocol . after this erp configuration has been performed , the failure of a link within the network will not require every network node to re - learn paths through the network ; instead , the nodes that are required to re - learn such paths can be limited to those within the particular ring that contained the failed link .