Default IP Address Behavior
When you connect a 1250 series access point running Cisco IOS Release 12.4(10b)JA or later software with a default configuration to your LAN, the access point requests an IP address from your DHCP server and, if it does not receive an IP address, continues to send requests indefinitely.
http://www.cisco.com/c/en/us/td/docs/wireless/access_point/1250/installation/guide/1250HIG_TD-Book-Wrapper/125h_c3.html
Traian