Filter
Top Products
DES-7200 Configuration Guide Chapter 5 RERP Configuration
5-1
5 RERP Configuration
5.1 RERP Overview
5.1.1 Understanding RERP
For the loop blocking and link recovery in core ring network, currently the OSPF and
BGP4 are mostly used for the implementation. For complex network, the link recovery
may take tens of seconds. If MSTP is used for loop blocking in the link layer, the STP
needs to advertise level by level by the spanning tree, the network convergence may
take rather long time in case of complicated network.
The Rapid Ethernet Ring Protection Protocol (RERP) is a special layer-2 link
redundancy backup protocol designed for core Ethernet. The loop blocking and link
recovery for the RERP are centrally implemented on the master device and the
non-master devices directly report their link conditions to the master device without
additional processing on the non-master devices; however the STP works with the
spanning tree to advertise level by level by the spanning tree and determine the final
link status through level-by-level calculations. So, the loop block and recovery with the
RERP are faster than those with the STP. Based on the above difference, the link
recovery of RERP in ideal environment may be completed in 50 microseconds.
The RERP involves the following key concepts: Region, Ring, Master, Backup, Transit,
Primary Edge Node, Secondary Edge Node, Primary Port, Secondary Port, Shared
Port and Control Vlan. They are explained through the following typical applications.
Note
As an alternative of STP in the core ring network, the RERP cannot be
turned on at the same time with the STP in the actual configurations.
RERP and REUP cannot share one port.