Administrator Guide

When creating an access list, the sequence of the filters is important. You have a choice of assigning sequence numbers to the
filters as you enter them, or the system assigns numbers in the order the filters are created. The sequence numbers are listed in
the display output of the show config and show ip accounting access-list commands.
Ingress and egress Hot Lock ACLs allow you to append or delete new rules into an existing ACL (already written into CAM)
without disrupting traffic flow. Existing entries in the CAM are shuffled to accommodate the new entries. Hot lock ACLs are
enabled by default and support both standard and extended ACLs and on all platforms.
NOTE: Hot lock ACLs are supported for Ingress ACLs only.
CAM Usage
The following section describes CAM allocation and CAM optimization.
● User Configurable CAM Allocation
● CAM Optimization
User-Configurable CAM Allocation
User-configurable content-addressable memory (CAM) allows you to specify the amount of memory space that you want to
allocate for ACLs.
To allocate ACL CAM, use the cam-acl command in CONFIGURATION mode. For information about how to allocate CAM for
ACL VLANs, see Allocating ACL VLAN CAM.
The CAM space is allotted in filter processor (FP) blocks. The total amount of space allowed is 12 FP Blocks. System flow
requires four blocks; these blocks cannot be reallocated.
The ipv4acl profile range is from 0 to 8. When configuring space foripv6acl, the total number of Blocks must equal 12. The
ipv6acl allocation must be a factor of 2 (2, 4). If allocation values are not entered for the CAM regions, the value is 0.
Save the new CAM settings to the startup-config (use write-mem or copy run start) then reload the system for the new
settings to take effect.
Test CAM Usage
The test cam-usage command is supported on the C9000 series.
This command applies to both IPv4 and IPv6 CAM profiles, but is best used when verifying QoS optimization for IPv6 ACLs.
To determine whether sufficient ACL CAM space is available to enable a service-policy, use this command. To verify the actual
CAM space required, create a class map with all the required ACL rules, then run the test cam-usage command in EXEC and
EXEC Privilege mode. The following example shows the output when running this command. The status column indicates
whether you can enable the policy.
● test cam-usage service-policy input policy-map-input-name {{linecard line-card-number port-set
port-set} | {linecard all [port-set port-set]} | { pe pe-id stack-unit stack-unit-number
port-set port-set}}
Parameters
● line card — Enter the linecard keyword and one of the following options:
○ linecard number (from 0 to 11) and then the port-set keyword and number.
○ All to specify all line card numbers and then the port-set keyword and number.
● stack-unit stack-unit-number — Enter the keyword stack-unit and then the stack unit number. The range is 0–7.
● pe pe–id — Enter the keyword pe and then the port-extender ID. The range is from 0 to 255
● port–set port–set — Enter the port-set keyword and then a port pipe/number. This is optional parameter with the
linecard all option.
● policy-input map policy-map-input-name — Enter the input policy map name (maximum of 32 characters).
Access Control Lists (ACLs)
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