Default Setting
None
Command Mode
Standard IPv4 ACL
Command Usage
• New rules are appended to the end of the list.
• Address bitmasks are similar to a s ubn et m ask , con taining four integers from
0 to 255, each separated by a period. The binary mask use s 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 add res s f or each I P
packet entering the port(s) to which this ACL has been assign ed.
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 (26-2)
permit, deny (Extended IPv4 ACL)
This command adds a rule to an Extended IPv4 ACL. The r ule sets a filter c ondit ion
for packets with specific source or destination IP addresses, protocol types, source
or destination protocol ports, or TCP control codes. U se the
no
form to remove a
rule.
Syntax
[no] {permit | deny} [protocol-number | udp]
{any | source address-bit mask | host sourc e}
{any | destination address-bitmask | host destination}
[precedence precedence] [tos to s] [dscp dscp]
[
source-port
sport [bitmask]] [
destination-port
dport [port-bitmask]]
[no] {permit | deny} tcp
{any | source address-bit mask | host source}
{any | destination address-bitmask | host destinat ion}
[precedence precedence] [tos to s] [dscp dscp]
[
source-port
sport [bitmask]] [
destination-port
dport [port-bitmask]]
[
control-flag
control-flags flag-bitmask]
• protoc ol-number – A specific protocol numb er. (Range: 0- 255)
• source – Source IP address.
• destination – Destinati on IP address.
• address-bitmask – Decimal number representing the address bits to match.
26-3IPv4 ACLs
26