Why do I have so many ANTI-SPOOFING?

Hello all, I have many ANTI-SPOOFINGs. I spoofed from my public IP to my broadcast and I do not why? Here is the log file that I got: Jun 5 14:49:55 server1 kernel: SuSE-FW-DROP-ANTI-SPOOFING IN=eth0 OUT= MAC= SRC=[My Public IP] DST=[My Public Broadcast] LEN=52 TOS=0x00 PREC=0x00 TTL=64 ID=0 DF PROTO=UDP SPT=520 DPT=520 LEN=32 Does it mean that someone tries to hack me? If it is, how can I protect myself from hacking? Thank you so much for your assistance. Best regards, Chan Choth