/var/log/kern.log
...Jun 26 09:07:45 gnu-linux-debian kernel: [ 11.325205] IPTables Packet Dropped: IN=eth0 OUT= MAC=ff:ff:ff:ff:ff:ff:54:04:a6:f3:45:60:08:00 SRC=192.168.1.147 DST=192.168.1.255 LEN=229 TOS=0x00 PREC=0x00 TTL=128 ID=33860 PROTO=UDP SPT=138 DPT=138 LEN=209...
應該是 147 發到 eth0
192.168.1.255 => 廣播給 192.168.1.xxx 內全部 ip
LEN=229 => IPv4 internet header length??
TOS=0x00 => IPv4, type of service, 0x00 16 進位是 0,沒有任何特殊條件??(ICMP 也有 TOS)
PREC=0x00 => IPv4,0x00 等於 routine??
TTL=128 => IPv4 time to live, 還有 128 跳,和 IPv6 Hop Limit 同性值??(ICMP 也有 TTL)
ID=33860 => IPv4 identification, 用於組合 fragmented 的包?? (ICMP 也有 TTL)
PROTO=UDP => protocol 是 UDP
SPT=138,DPT=138 => 原端口,目地端口都是138,微軟 netbios 的通信??
LEN=209 => 這應該是 UDP 的??