The Auto channel selection will let Datto optimize channel settings for your network. Auto channel scans occur during your maintenance window and channel adjustments will happen during that time. You'll want to make sure that your maintenance window is during a low traffic time period because channel changes can cause some temporary disconnects for clients. If no changes are required the potential disruption to the network will be minimal -- around 5-10 seconds. If changes are required then the AP will reconfigure, taking the network interfaces down for about ~30 seconds.
While auto channel is enabled any existing overrides are overridden by auto channel. If auto channel is later disabled, the user’s original channel overrides, if any, will again be used.
The automatic channel feature will use channels that are as uniform as possible, avoid channels which are used by other APs, minimize the number of hops in the mesh, maximize client throughput, ensure better connections between nodes, and avoid orphaned mesh nodes.
From our scan results, we create a graph of possible mesh connections and assign channels to gateways by trying to avoid external interference (APs, spectrum scan results). We then assign channels for gateways with the smallest amount of channel alternatives and/or the most interference nearby. If a gateway is a dual-band device, we assign channels independently for each band as per the goals above.
All repeater nodes get a channel assigned and we compute scores for all possible edges. A "possible edge" is between an unassigned node and an assigned node. Our scoring takes into account: outside interference, link quality, and capacity of the assigned node. We then assign a channel to the node with the best scored possible edge. if the repeater is a dual-band device, we treat the second band as if it's a gateway and assign channels independently just the same.