Everything Instant On

While creating a new site, we will get an option to enter the device Serial Number manually if the device is not discovered automatically. Likewise, If there is an AP connected and UP on the same site, we will not get an option to enter the device serial number manually. The only way to add the new device is through the automatic discovery process.

If we want to add more APs to the same site, it should be part of the same subnet. If you move an AP from the existing site to a different subnet it will act as a sperate master irrespective of its being part of the same site. This scenario is called as "Split-site". 

This is not a supported design and not recommended by Aruba as many features will not work if APs are part of the same site but on a different subnet.

Which features will not work while using Split-Site? What problems do I have to expect when using Split-Site?

To be a little bit more specific: I've got the situation where I have around 15 Instant On Access-Points in Private Network Mode located at 15 different locations. Any of these Access-Points are connected over an 4G-Router to internet. The local subnet on each site is equal and the 4G-Router will act as DHCP-server. The SSID on each location should be identical.

To keep it simple I would like to summarize all those 15 AP's within one single site. As a test I was able to add 3 access-points behind 3 different 4G-Routers to the same site. So far this seems to work just fine, also if the local IP-adress of the AP does overlapp. So which features do I have to expect that are not working properly within this scenario?