Service Manual

Test CAM Usage
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 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. If you do not assign an IP ACL to an interface, it is not used by
the software.
The number of entries allowed per ACL is hardware-dependent.
If counters are enabled on ACL rules that are already configured, those counters are reset when a new
rule which is inserted or prepended or appended requires a hardware shift in the flow 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 flow in the hardware, the counters are not affected. This is applicable to the following
features:
• L2 Ingress Access list
• L2 Egress Access list
NOTE: IP ACLs are supported over VLANs in Dell Networking OS version 6.2.1.1 and higher.
Assigning ACLs to VLANs
When you apply an ACL to a VLAN using single port-pipe, a copy of the ACL entries gets installed in the
ACL CAM on the port-pipe. The entry looks for the incoming VLAN in the packet. When you apply an ACL
on individual ports of a VLAN, separate copies of the ACL entries are installed for each port belonging to a
port-pipe.
You can use the log keyword to log the details about the packets that match. The control processor
becomes busy based on the number of packets that match the log entry and the rate at which the details
are logged in. However, the route processor (RP) is unaffected. You can use this option for debugging
issues related to control traffic.
ACL Optimization
If an access list contains duplicate entries, Dell Networking OS deletes one entry to conserve CAM space.
Standard and extended ACLs take up the same amount of CAM space. A single ACL rule uses two CAM
entries to identify whether the access list is a standard or extended ACL.
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Access Control Lists (ACLs)