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Most ACL rules require one entry in the CAM. However, rules with TCP and UDP
port operators (for example, gt, lt or range) may require more than one entry. The
range of ports is configured in the CAM based on bit mask boundaries; the space
required depends on exactly what ports are included in the range.
Example
An ACL rule with a TCP port range of 4000–8000 uses eight entries in the CAM.
Rule# Data Mask From To #Covered
1 0000111110100000 1111111111100000 4000 4031 32
2 0000111111000000 1111111111000000 4032 4095 64
3 0001000000000000 1111100000000000 4096 6143 2048
4 0001100000000000 1111110000000000 6144 7167 1024
5 0001110000000000 1111111000000000 7168 7679 512
6 0001111000000000 1111111100000000 7680 7935 256
7 0001111100000000 1111111111000000 7936 7999 64
8 0001111101000000 1111111111111111 8000 8000 1
Total Ports: 4001
Example
An ACL rule with a TCP port lt 1023 uses only one entry in the CAM.
Rule# Data Mask From To #Covered
1 0000000000000000 1111110000000000 0 1023 1024
Total Ports: 1024
Related
Commands
deny — assigns a filter to deny IP traffic.
deny tcp — assigns a filter to deny TCP traffic.
ip access-list extended
Name (or select) an extended IP access list (IP ACL) based on IP addresses or protocols.
Syntax
ip access-list extended access-list-name
To delete an access list, use the no ip access-list extended access-
list-name command.
Parameters
access-list-
name
Enter a string up to 140 characters long as the access list
name.
Defaults All access lists contain an implicit “deny any”; that is, if no match occurs, the packet
is dropped.
Command
Modes
CONFIGURATION
Command
History
This guide is platform-specific. For command information about other platforms,
refer to the relevant Dell Networking OS Command Line Reference Guide.
Access Control Lists (ACL)
249