SMC Networks SMC6724L3 L, I, 4-80

C OMMAND L INE I NTERFACE
4-80
•host – Keyword followed by a specific IP address.
•source-port – TCP/UDP source port number. (Range: 0-65535)
•destination-port – TCP/UDP destination port number. (Range:
0-65535)
•protocol-number – A specific protocol number. (Range: 0-255)
•control-code – Decimal number (representing a bit string) that specifies
flag bits in byte 14 of the TCP header. (Range: 0-63)
•code-bitmask – Decimal number representing the code bits to match.
Default Setting
None
Command Mode
Extended ACL
Command Usage
• All new rules are added to the end of the list.
• Address bitmasks are similar to a subnet mask, containing four integers
from 0 to 255, each separated by a period. The binary mask uses 1 bits
to indicate “match” and 0 bits to indicate “ignore.” The bitmask is
bitwise ANDed with the specified source IP address, and then
compared with the address for each IP packet entering the port(s) to
which this ACL has been assigned.
• The control-code bitmask is a decimal number (representing an
equivalent 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 2”