AP registration fails in remote subnet

[Andre_Scheper]

I have a strange Problem:

On my V2110 Controller I use the esa0 Interface for the AP registration.

If my AP's (Siemens AP2610) are in the same subnet, everythings works
fine. Now i want to bring one AP to a remote subnet, the registration fails, but the controller knows the new AP IP address (172.18.24.0/24). I can telnet the AP and ping the controller and the controller can ping the AP (no firewall between them). There is also a DNS Record "controller.domain.name" pointing to the 172.18.31.25

So there must be a communication between AP and EWC, because i can ping and enable/disble Telnet. But the AP is not shown in the active AP list.

I don't know where I misconfigured it.

[Andre_Scheper]

There is (currently) no VPN in between.
For testing purposes its just another subnet in my office. So MTU shouldn't be a problem.

After the reset, the AP gets a remote IP address via DHCP and also the EWC IP via DHCP Option 78.
THe AP connects to the EWC and appoves it:

But it is still not active

The LED states on the AP are:
Left: solid green
Center: blinking green
Right: off
Documentation says: "Connecting to Enterasys Wireless Controller: Upgrading to higher version"

The AP console session shows the following:

There is no 802.1x configruation on the Switch-Port.

[Ronald_Dvorak]

Andre,

I'd do it from scratch.
If there is an DHCP server in the subnet of the AP it's an easy task.
telnet to the AP and clear the config = set factory
delete the AP in the EWC database = in access approvel delete the AP
after the AP is back with no config (beside the IP/mask,gateway from DHCP) set the controller IP via a static entry = set authip 1 172.18.31.25

is the link from the EWC to the AP via a VPN with a lower MTU ?

Ron