Thanks Rajaganesh.
I try to capture the packet on site server subnet (pic1.jpg). It ONLY has a magicpacket to 255.255.255.255 from the site server (IP : xxx.xxx.zzz.37) and the MAC address is correct (i.e. the PC wanted to be wake up). There is no 2nd packet shown in the reference:
http://www.symantec.com/business/support/index?page=content&id=TECH38547
Also, I cannot capture any WOL packet in client subnet.
It seems the site server didn't send WOL packet to its gateway (xxx.xxx.zzz.255).
I try to setup another site server, assign the client PC to be managed by it but still having the same result.
Any more idea based on these information?
Thanks.
Note: The client PC can be waken up if it is placed in same subnet with site server. So, the BIOS setting of client PC should be correct.