Service Manual

CAM Usage
The following section describes CAM allocation and CAM optimization.
• User Congurable CAM Allocation
• CAM Optimization
User Congurable CAM Allocation
Allocate space for IPV6 ACLs by using the cam-acl command in CONFIGURATION mode.
The CAM space is allotted in lter processor (FP) blocks. The total space allocated must equal 13 FP blocks. (There are 16 FP blocks,
but System Flow requires three blocks that cannot be reallocated.)
Enter the ipv6acl allocation as a factor of 2 (2, 4, 6, 8, 10). All other prole allocations can use either even or odd numbered
ranges.
If you want to congure ACL's on VRF instances, you must allocate a CAM region using the vrfv4acl option in the cam-acl command.
Save the new CAM settings to the startup-cong (use write-mem or copy run start) then reload the system for the new
settings to take eect.
CAM Optimization
When you enable this command, if a policy map containing classication rules (ACL and/or dscp/ ip-precedence rules) is applied to
more than one physical interface on the same port-pipe, only a single copy of the policy is written (only one FP entry is used). When
you disable this command, the system behaves as described in this chapter.
Test CAM Usage
This command applies to both IPv4 and IPv6 CAM proles, but is best used when verifying QoS optimization for IPv6 ACLs.
To determine whether sucient 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 execute the test cam-usage command in Privilege mode.
The following example shows the output when executing this command. The status column indicates whether you can enable the
policy.
Example of the test cam-usage Command
Dell#test cam-usage service-policy input asd stack-unit 1 port-set 0
Stack-unit|Portpipe|CAM Partition|Available CAM|Estimated CAM per Port|Status
--------------------------------------------------------------------------
1| 1| IPv4Flow| 232| 0|Allowed
Dell#
Implementing ACLs on Dell Networking OS
You can assign one IP ACL per interface with Dell Networking OS. If you do not assign an IP ACL to an interface, it is not used by the
software in any other capacity.
The number of entries allowed per ACL is hardware-dependent. For detailed specication on entries allowed per ACL, refer to your
line card documentation.
If counters are enabled on ACL rules that are already congured, those counters are reset when a new rule which is inserted or
prepended or appended requires a hardware shift in the ow table. Resetting the counters to 0 is transient as the proginal counter
values are retained after a few seconds. If there is no need to shift the ow in the hardware, the counters are not disturbed. This is
applicable to the following features:
108
Access Control Lists (ACLs)