currently I have addressed all the AP's in one of the subnets for management, but now there is an issue with dhcp size. Therefore, i have created a separate subnet for management of the AP's only, that won't be used for over the air wireless.
The problem i have experienced is when i added new ip address / subnet / vlan to the AP's i could not get my clients to gain an IP address via dhcp anymore in vlans 2 & 3.
new subnet 5.x.x.5 /24 vlan 5 - management only - native vlan.
all AP's connect onto 4500 series switches where routed VLAN interfaces are the default gw. DHCP server for the clients is physically attached in vlan 3 220.127.116.11 subnet with ip helper on vlan 2 interface 2.x.x.2 on the switch.
I have subsequently re-addressed all devices to be back in native vlan 2 with IP addresses allocated to AP's within that range for management purposes also - all clients can now obtain an IP address via dhcp.
Could this possibly be an arp / mac cache issue or something bigger?
I have sorted the problem. At present we don't currently look after the radius server (soon will be hopefully), but assumed that they had added the NAS devices. The new subnet that I wished to use as a management subnet was not identified as a NAS, thus the access could not reach the radius server, thus the EAP method was not available.