Power issues for site

[SteveHen]

Hi, I have a site that is going to experience power issues. We will need a generator at site and maybe some UPS.

The site are also planning on having a power down overnight. This will take the switches, APs and SD WAN offline.

When the power comes on again it will take the SD WAN a few minutes to come online and build the tunnels. As the switches will come up at the same time when the power comes on for the whole site the switches will look to get their configuration but this will not be available while the SD WAN is not running. 

So my question is how often will the Meraki switches try to get their configuration when they boot up without it. Is there a way I can look to save a configuration on these devices.

Thanks, Steve

[RWelch · Accepted solution]

In the event of cloud connectivity loss (which is most commonly caused by a local ISP or connection failure), the Meraki hardware device will continue to run with its last known configuration until cloud connectivity is restored.

Meraki Cloud Architecture 

If a device is offline, it will continue to attempt to connect to the Meraki cloud until it gains connectivity. Once the device comes online, it automatically receives the most recent configuration settings from the Meraki cloud. If changes are made to the device configuration while the device is online, the device receives and updates these changes automatically. These changes are generally available on the device in a matter of seconds. However, large quantities of changes may take noticeably longer to reach their devices. If no configuration changes are made by the user, the device continues to periodically check for updates to its configuration on its own.

Short answer:
Meraki switches will boot and operate using their last known good configuration even if they cannot immediately reach the Meraki cloud. They will continue retrying cloud connectivity indefinitely. There is no local configuration storage that you can manage manually, but the device automatically retains its most recent working config.

[SteveHen]

Do you know how long it would take a switch to startup when it has already had a configuration and is staying in the same location with the same configuration and firmware? I am trying to ensure that devices depending on these switches for DHCP will be serviced or determine if they need a UPS or if devices around site should simply be switched off so that they can be switched on in the morning and get the address from DHCP as the switch would have booted by then. The switches are also inline. SD WAN - DS - AS - AS - AS due to the cabling at site. Do we need to wait for each switch to gain its config before the next one will?

[Mloraditch]

The boot time is variable depending on the platform, most MS switches I'd say are 3-5 minutes, IOS-XE could be longer ~10-15, but all of that can also depend on firmware CS IOS-XE will be slower than regular IOS-XE, etc. To be clear the switches don't gain their config, they will have it already. Unless you are making changes while they are offline they will boot up and not need to apply any new config.

If they all  boot simultaneously they will come online nearly simultaneously. If you have concerns that devices won't recover correctly if the network is not fully online, I suggest you have them powered off or just inform the end users that they may need to reboot first thing.

[BeverlyManfredi]

Thank you, you saved my day.