We have Juniper EX8208 chassis based switch running in a production environment. The switch has 2 REs running in active and standby role with RE0 being the primary routing engine. The device is providing Layer 2 switching services with no routing protocols are running on it.

We need to perform routing engine switchover to make RE1 master. However we are not sure that during the switchover , will FPCs reboot or not? In case the FPCs reboot , is there any way to prevent FPCs from rebooting during routing engine switchover.

The chassis redundancy is configured but we have not configured non stop routing on EX8200 switch.

user@ESW-EX82> show configuration chassis redundancy
routing-engine 0 master;
routing-engine 1 backup;
failover {

user@ESW-EX82> show configuration routing-options | match nonstop-routing 


  • 1
    In theory, they shouldn't. Unless you're logged into the RE, you shouldn't even notice the switchover. But being in the Real World(tm), plan for things not going perfectly. (i.e. do this when you can most tolerate the disruption.)
    – Ricky
    Aug 19, 2021 at 17:11
  • Did any answer help you? if so, you should accept the answer so that the question does not keep popping up forever, looking for an answer. Alternatively, you could post and accept your own answer.
    – Ron Maupin
    Dec 23, 2021 at 21:31

1 Answer 1


I have found answer from the Juniper documentation as below:-

The graceful Routing Engine switchover (GRES) feature in Junos OS and Junos OS Evolved enables a router with redundant Routing Engines to continue forwarding packets, even if one Routing Engine fails. GRES preserves interface and kernel information. Traffic is not interrupted. However, GRES does not preserve the control plane.

Below is the official Juniper documentation link.


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