CLI Reference Guide-R04

Chapter 10 | Access Control Lists
IPv4 ACLs
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permit, deny
(Standard IP ACL)
This command adds a rule to a Standard IPv4 ACL. The rule sets a filter condition for
packets emanating from the specified source. Use the no form to remove a rule.
Syntax
{permit | deny} {any | source bitmask | host source}
[time-range time-range-name]
no {permit | deny} {any | source bitmask | host source}
any – Any source IP address.
source – Source IP address.
bitmask – Dotted decimal number representing the address bits to match.
host – Keyword followed by a specific IP address.
time-range-name - Name of the time range. (Range: 1-32 characters)
Default Setting
None
Command Mode
Standard IPv4 ACL
Command Usage
◆ New rules are appended to the end of the list.
◆ Address bit masks 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.
Example
This example configures one permit rule for the specific address 10.1.1.21 and
another rule for the address range 168.92.16.x – 168.92.31.x using a bitmask.
Console(config-std-acl)#permit host 10.1.1.21
Console(config-std-acl)#permit 168.92.16.0 255.255.240.0
Console(config-std-acl)#
Related Commands
access-list ip (382)
Time Range (177)