I'm trying to get a stable UDM after experiencing the UDM Network App dying regularly

https://community.ui.com/questions/Network-Application-Crashing-on-UDM-Base-over-time-Network-10-4-57-and-UnifiOS-5-1-19/e197b6b8-9076-47b6-8fcf-2f69aaa4f88e?reply=10

I have tried a few things

1. Upgrade to Early Access versions (still the network app dies)
2. Disable IDS/IPS (still the network app dies after disabling it)

Now trying factory reset and restore a backup taken before the Network App dying randomly became a problem

Things to note

After a Factory Reset - Configure your Internet Connection First

When you do a factory reset you cannot stay offline and successfully restore a backup which is linked to your unifi.ui.com account.

The UDM has to be configured with the same owner as before, or the backups taken under that account won't install.

So first thing after the factory reset is get connected back to the internet (don't try to do an offline configure or upload a backup from your local PC that was created by a specific Unifi Account)

I ended up doing 2 Factory Resets to get things right. I needed to connect to the UDM using a network cable and the default http://192.168.1.1 configure the internet connection

Have your ISP internet connection details available before the factory reset

I use Exetel so for me the settings on HFC NBN are

PPPoE

User [email protected] and a password

This will get your IPv4 stack running and that will allow you to authenticate with the Unifi cloud and install one of the cloud account stored backups.

Login to the UDM local web page with your unifi.ui.com account that owns the UDM

After getting your UDM connected to the internet, login using your Unifi account (the one you use for unifi.ui.com) and then all the automatic backups will be available and you can just restore any from the list.

Other Unifi Devices

The Unifi devices that were previously adopted by your UDM will re-adopt.

If you port assignments for the UDM and any switches have changed you might need to edit your UDM and Switch port settings to put the Unifi devices on the "management" network if you have one, and any other devices to the right subnets if you use them.

You may need to power cycle your Unifi WAPs and Switches especially if you have done some port edits

IPv4 will get you running but IPv6 needs re-adding too

I had IPv6 before the restore but I needed to reconfigure IPv6 on the WAN connection to get my IPv6 enabled subnets back.

If your restored backup is a few months old you may need to do some tidy tidy if things have changed.

VPN Servers and Site to Site Links

If all the above is correct then VPN servers and VPN connections will be successfully restored and won't need tweaking to work.