If you open this link to see 5GHz channel allocation you will find 2 green blocks. The first block has channels 36, 40, 44, and 48. The second block has channels 149, 153, 157, 161, and 165. As far as I understand, these blocks can be used in any country. As a result, many routers only allow you to choose only these channels for a 5 GHz network. All channels between these are co-called DFS channels, and their usage is different in each country.

DFS channels have some rules that are different in each country and that routers must follow.

But what will happen if you try to use any of those DFS channels? For example, let’s try to