client to Site PPTP access all of IP Groups

Hi all;

i have a interesting problem about client to site VPN problem.i have 4 IP(two of them is A class,remainig two is C class) groups in local,and all of them public ip. when i connect via VPN to site(if remote ip in PPP secrets on winbox is arranged A class) i can access a class network but cannot access to C class. the exact opposite situation is same.

i configured local interface as proxy-arp and i dont understand why?

thank you