When meet Issue about RRPP ring status on S7700 .

Issue Description

1. Topology

2. After configured, the sub ring status is preforwarding on S7700
RRPP Ring      : 2
Ring Level     : 1
Node Mode    : Edge Transit
Ring State     : PreForwarding
Is Enabled     : Enable                             Is Active: Yes
Primary port   : Ethernet2/0/2                 Port status: UP
Ethernet2/0/3                 Port status: UP
Secondary port : Ethernet2/0/5              Port status: BLOCKED

Alarm Information

None

Handling Process

Check all configuration on device. Found that RRPP working-mode is GB on S7700, but on S57 it is HW mode. Because of different mode, there are different node and configuration on Switch.
Let customer change RRPP working-mode to HW same with S5700 and test it works fine.

Root Cause

1. Wrong Configuration
2. RRPP calculation Issue

Suggestions

1. Changing RRPP working-mode needs to disable RRPP first and delete the old configuration
2. On S5700, RRPP only supports HW  working-mode and cannot be configured. S7700 supports both modes.