Purpose
Command or Action
Source, source-wildcard, destination, and destination-wildcard can be specified
as:
•
The 32-bit quantity in dotted-decimal format.
•
The keyword
any
for 0.0.0.0 255.255.255.255 (any host).
•
The keyword
host
for a single host 0.0.0.0.
The other keywords are optional and have these meanings:
•
precedence
—
Enter to match packets with a precedence level specified
as a number from 0 to 7 or by name:
routine
(0),
priority
(1),
immediate
(2),
flash
(3),
flash-override
(4),
critical
(5),
internet
(6),
network
(7).
•
fragments
—
Enter to check non-initial fragments.
•
tos
—
Enter to match by type of service level, specified by a number from
0 to 15 or a name:
normal
(0),
max-reliability
(2),
max-throughput
(4),
min-delay
(8).
•
log
—
Enter to create an informational logging message to be sent to the
console about the packet that matches the entry or
log-input
to include
the input interface in the log entry.
•
time-range
—
Specify the time-range name.
•
dscp
—
Enter to match packets with the DSCP value specified by a
number from 0 to 63, or use the question mark (?) to see a list of available
values.
If you enter a
dscp
value, you cannot enter
tos
or
precedence
. You
can enter both a
tos
and a
precedence
value with no
dscp
.
Note
Defines an extended TCP access list and the access conditions.
access-list access-list-number
{
deny
|
permit
}
tcp source source-wildcard
[
operator port
]
Step 3
The parameters are the same as those described for an extended IPv4 ACL,
with these exceptions:
destination destination-wildcard
[
operator
port
] [
established
] [
precedence precedence
]
(Optional) Enter an
operator
and
port
to compare source (if positioned after
source source-wildcard
) or destination (if positioned after
destination
[
tos tos
] [
fragments
] [
log
[
log-input
]
[
time-range time-range-name
] [
dscp dscp
]
[
flag
]
destination-wildcard
) port. Possible operators include
eq
(equal),
gt
(greater
than),
lt
(less than),
neq
(not equal), and
range
(inclusive range). Operators
require a port number (range requires two port numbers separated by a space).
Example:
Switch(config)#
access-list 101 permit
Enter the
port
number as a decimal number (from 0 to 65535) or the name of
a TCP port. Use only TCP port numbers or names when filtering TCP.
tcp any any eq 500
The other optional keywords have these meanings:
•
established
—
Enter to match an established connection. This has the
same function as matching on the
ack
or
rst
flag.
•
flag
—
Enter one of these flags to match by the specified TCP header
bits:
ack
(acknowledge),
fin
(finish),
psh
(push),
rst
(reset),
syn
(synchronize), or
urg
(urgent).
Catalyst 2960-X Switch Security Configuration Guide, Cisco IOS Release 15.0(2)EX
158
OL-29048-01
Configuring IPv4 ACLs
Creating a Numbered Extended ACL