Unified ISSU: EVPN and VXLAN

Junos OS supports Unified ISSU on EVPN and VXLAN. Unified ISSU enables you to upgrade between two different Junos OS releases with no disruption on the control plane and with minimal disruption of traffic. Unified ISSU upgrade is only supported by dual Routing Engine platforms. Unified ISSU requires both GRES and NSR to be enabled. To enable GRES, include the graceful-switchover statement at the [edit chassis redundancy] hierarchy level. To enable NSR, include the nonstop-routing statement at the [edit routing-options] hierarchy level and the commit synchronize statement at the [edit system] hierarchy level.