Introduction

Juniper Apstra supports Drain Mode for managed switches, allowing the operator to gracefully drain traffic from devices without simply shutting down the BGP neighbor relationships. This is implemented through modifications to the BGP process (inbound/outbound route-maps), shutting down connected L2 server ports, and shutting down MLAG peer link ports. By using Drain Mode, operators can minimize the number of dropped/lost traffic during these operations. During maintenance, redundancy is handled by ECMP/MLAG as long as there are suitable redundant systems in place. A visual example of Drain Mode on Spine switches is displayed below: