Hi Julian,
If i understand correctly , IAP's need to be configured with static IP's belonging to vlan 800.
However, vlan 800 will be tagged on the uplink port (switch side).
If my understnading is correct, you can try the following:
1. Connect the IAP's to the switch.
2. Initially IAP can not tag any packets as uplink management vlan is set to 0 by default.
3. So, it will send DHCP DISCOVER packets on native vlan.
"As there is no DHCP service on the network, the IAP obtains an IP automatically within the 169.254 subnet.
4. The instant SSID should be available to connect a client.
Connect a wireless client to instant SSID & navigate to "instant.arubanetworks.com".
We should get the login prompt for the WebUI. The default credentials are admin/admin.
5. Once you are logged into Web UI, you can assign static IP's to the IAP's & change their uplink management vlan to 800.
We need to reboot the IAP's in order for these changes to take effect.
So, once you have set static IP's/uplink management vlan on all the IAP's, you can reboot them from the Web UI.
Note: if possible, try these steps on 2-3 IAP's initially . If everything works as expected, you can congfiure the remaining IAP's accordingly.