Access Control Lists
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•Protocol – Specifies the protocol type to match as TCP, UDP or Others, where
others indicates a specific protocol number (0-255). (Options: TCP, UDP, Others;
Default: TCP)
•Src/Dst Port – Source/destination port number for the specified protocol type.
(Range: 0-65535)
•Src/Dst Port Bitmask – Decimal number representing the port bits to match.
(Range: 0-65535)
•Control Code – Decimal number (representing a bit string) that specifies flag bits
in byte 14 of the TCP header. (Range: 0-63)
•Control Bitmask – Decimal number representing the code bits to match.
The control bitmask is a decimal number (for an equivalent binary bit mask) that is
applied to the control code. Enter a decimal number, where the equivalent binary
bit “1” means to match a bit and “0” means to ignore a bit. The following bits may
be specified:
- 1 (fin) – Finish
- 2 (syn) – Synchronize
- 4 (rst) – Reset
- 8 (psh) – Push
- 16 (ack) – Acknowledgement
- 32 (urg) – Urgent pointer
For example, use the code value and mask below to catch packets with the
following flags set:
- SYN flag valid, use control-code 2, control bitmask 2
- Both SYN and ACK valid, use control-code 18, control bitmask 18
- SYN valid and ACK invalid, use control-code 2, control bitmask 18