Managing Stateful Line Module Switchover

This chapter describes how to manage stateful line module switchover (high availability) software features for E120 and E320 routers, and contains the following sections:

• Stateful Line Module Switchover Overview
• Benefits of Stateful Line Module Switchover
• Stateful Line Module Switchover Platform Considerations
• Guidelines for Configuring Stateful Line Module Switchover
• System Operations When Stateful Line Module Switchover Is Enabled
• Stateful Line Module Configuration Scenarios
• Replacement of Line Modules When Stateful Line Module Switchover Is Enabled
• Application Support for Stateful Line Module Switchover
• Stateful Line Module Switchover Modes
• Stateful Line Module Switchover States
• Guidelines for Activating High Availability
• Activating High Availability
• Guidelines for Deactivating High Availability
• Deactivating High Availability
• Switching Over from a Primary Line Module to Secondary Line Module
• Log Messages Generated for Stateful LM Switchover
• Preservation of Statistics During Stateful Line Module Switchover
• Performance Impact and Scalability Considerations
• Use of Status LEDs to Monitor the High Availability States of Line Modules
• Monitoring the Redundancy Status of Line Modules in a Specific Slot
• Monitoring the Redundancy History of Line Modules in a Specific Slot