Administrator Guide

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.
NOTE: Hot lock ACLs are supported for Ingress ACLs only.
Implementing ACL on the Dell
Networking OS
You can assign one IP ACL per interface with the 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 specification on entries allowed
per ACL, refer to your line card documentation.
If you enable counters on IP ACL rules that are already configured, those counters are reset when a new rule
is inserted or prepended. If a rule is appended, the existing counters are not affected. This is applicable to the
following features:
• L2 Ingress Access list
• L2 Egress Access list
• L3 Ingress Access list
• L3 Egress Access list
NOTE
: IP ACLs are supported over VLANs in the Dell Networking OS version 6.2.1.1 and higher.
ACLs and VLANs
There are some differences when assigning ACLs to a VLAN rather than a physical port.
For example, when using a single port-pipe, if you apply an ACL to a VLAN, one copy of the ACL entries is
installed in the ACL CAM on the port-pipe. The entry looks for the incoming VLAN in the packet. Whereas if
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.
ACL Optimization
If an access list contains duplicate entries, the system 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
whether it is identified as a standard or extended ACL.
Access Control Lists (ACLs) 128