IP ACLs
23-3
23
Default Setting
None
Command Mode
Standard IP ACL
Command Usage
• New rules are appended 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.
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.
Related Commands
access-list ip (23-2)
permit, deny (Extended ACL)
This command adds a rule to an Extended IP ACL. The rule sets a filter condition for
packets with specific source or destination IP addresses, protocol types, source or
destination protocol ports, or TCP control codes. Use the no form to remove a rule.
Syntax
[no] {permit | deny} [protocol-number | udp]
{any | source address-bitmask | host source}
{any | destination address-bitmask | host destination}
[precedence precedence] [tos tos] [dscp dscp]
[source-port sport [bitmask]] [destination-port dport [port-bitmask]]
[no] {permit | deny} tcp
{any | source address-bitmask | host source}
{any | destination address-bitmask | host destination}
[precedence precedence] [tos tos] [dscp dscp]
[source-port
sport [bitmask]] [destination-port dport [port-bitmask]]
[control-flag control-flags flag-bitmask]
• protocol-number – A specific protocol number. (Range: 0-255)
• source – Source IP address.
• destination – Destination IP address.
• address-bitmask – Decimal number representing the address bits to match.
• host – Keyword followed by a specific IP address.
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)#
To Next Page
Loading...
Need help?
General