Enter Maintenance Mode Before Upgrading Software

Maintenance mode helps to minimize traffic loss during planned maintenance operations such as software upgrades.

About this task

Planned maintenance operations may require the device to be shut down or restarted, resulting in traffic disruption even if alternative paths are available. Maintenance mode provides graceful traffic diversion to alternative traffic paths, helping to minimize traffic loss during such planned operations.

When an alternative path is available, the BGP and MCT protocols redirect traffic away from the node that is going into maintenance mode. When maintenance mode is enabled, all protocols that are running on the maintenance mode node are notified and redirection of traffic (convergence) begins in stages.

Note

Maintenance mode is not supported for the following features: BGP address-family, Flowspec, Layer 3 VPN, VPLS, and VLL (virtual leased line).

Procedure

Access configuration mode.
```
device# configure terminal
```
Access system mode.
```
device(config)# system
```
Access system maintenance mode.
```
device(config-system)# maintenance
```

Enable maintenance mode.

device(config-system-maintenance)# enable

Specify the number of seconds allowed per stage of the convergence of traffic to the maintenance mode node.
```
device(config-system-maintenance)# convergence-time 125
```
This example sets the convergence time to 125 seconds.

Example

The following example summarizes the commands in this procedure.

device# configure terminal
device(config)# system
device(config-system)# maintenance
device(config-system-maintenance)# enable
device(config-system-maintenance)# convergence-time 125