bit
operator
port port
destination
mask
count
bytes
order
Access Control Lists (ACL)
Enter a flag or combination of bits:
•
ack: acknowledgement field
•
fin: finish (no more data from the user)
•
psh: push function
•
rst: reset the connection
•
syn: synchronize sequence numbers
•
urg: urgent field
(OPTIONAL) Enter one of the following logical operand:
•
eq = equal to
•
neq = not equal to
•
gt = greater than
•
lt = less than
•
range = inclusive range of ports (you must specify two
ports for the port command)
Enter the application layer port number. Enter two port
numbers if using the range logical operand. The range is
from 0 to 65535.
The following list includes some common TCP port
numbers:
•
23 = Telnet
•
20 and 21 = FTP
•
25 = SMTP
•
169 = SNMP
Enter the IP address of the network or host to which the
packets are sent.
Enter a network mask in /prefix format (/x) or A.B.C.D. The
mask, when specified in A.B.C.D format, may be either
contiguous or non-contiguous.
(OPTIONAL) Enter the keyword count to count packets the
filter processes.
(OPTIONAL) Enter the keyword byte to count bytes the filter
processes.
(OPTIONAL) Enter the keyword order to specify the QoS
priority for the ACL entry. The range is from 0 to 254 (where
0 is the highest priority and 254 is the lowest; lower-order
numbers have a higher priority) If you did not use the
keyword order, the ACLs have the lowest order by default
(255).
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