The UDM is a unique product in the UniFi line. Most UniFi devices are standalone, and it’s up to you to pick which are right for your network. With the UDM, Ubiquiti made those choices for you. You can think of the UDM as a UniFi starter kit. Integrating all the components in one device has a lot of benefits, but also some limitations. It also complicates the upgrade path from a USG-based network. Ubiquiti is working on a direct replacement for the USG, more on that later.

If you’re interested in my full review of the UDM, you can find that here.

UDM Complications: Built-In Controller, missing features

Since the UDM and UDM-Pro run a new operating system underneath, and have built-in controllers, they don’t always act like other UniFi devices.

Dream Machines are not able to be adopted by another controller, which can complicate remote or multi-site management. If you have multiple UDM sites, you are able to sign into your UI.com account on those devices, and manage them all through Ubiquiti’s free cloud service. You are not able to manage them as sites within another UniFi controller, like a Cloud Key or self-hosted UniFi controller.

The UDM is also a younger product than the USG. With that comes some instability and a lot of missing features. Some of those features listed may not affect you, but basic things like multiple IPs, VLANs, or DHCP options on a WAN interface, dynamic routing, and a lot of IPv6 features are not there yet. With the USG, you might be able to hack together a configuration to get around the limits, but with the UDM you can not. I know some people require DHCP options on their WAN interface from their ISP, and it’s baffling that basic features like that are not supported yet.

The UDM and UDM-Pro run UbiOS, which is Ubiquiti’s new proprietary Linux distro. Documentation is sparse, but most standard Linux commands will work, and most USG commands will not work on the UDM. Some features are able to be configured via the command line, but the UDM lacks the config file system of the USG. In general, command line changes do not play well with the UniFi controller software. Firmware updates may wipe your configurations, or cause instability. Proceed at your own risk.

The features and abilities that are implemented on the UDM are good, just keep these limits in mind when considering purchasing. I would advise against buying any product with the hope that future software updates will address a missing feature you need.

UDM-Pro

Another option is the UDM-Pro, which was just released in early 2020. It is a 1U appliance, made out of metal. It looks similar to the USG-Pro, with a few added features and much faster performance.