November, 2004: Practical Secure Port Knocking

Aug 11 10:00:46 kernel: FIREWALL:SRC=192.168.0.5 DST=192.168.0.3
LEN=60 TOS=0x10 PREC=0x00 TTL=64 PROTO=TCP SPT=32769 DPT=42
Aug 11 10:00:55 kernel: FIREWALL:SRC=192.168.0.5 DST=192.168.0.3
LEN=60 TOS=0x10 PREC=0x00 TTL=64 PROTO=TCP SPT=32770 DPT=196
Aug 11 10:00:57 kernel: FIREWALL:SRC=192.168.0.5 DST=192.168.0.3
LEN=60 TOS=0x10 PREC=0x00 TTL=64 PROTO=TCP SPT=32771 DPT=69

Example 1: Log entries (emphasis added).

Back to Article