Users Guide

Congure Layer 2 and Layer 3 ACLs
Both Layer 2 and Layer 3 ACLs may be congured on an interface in Layer 2 mode.
If both L2 and L3 ACLs are applied to an interface, the following rules apply:
• When Dell Networking OS routes the packets, only the L3 ACL governs them because they are not ltered against an L2 ACL.
• When Dell Networking OS switches the packets, rst the L3 ACL lters them, then the L2 ACL lters them.
• When Dell Networking OS switches the packets, the egress L3 ACL does not lter the packet.
For the following features, if you enable counters on rules that have already been congured and a new rule is either inserted or prepended,
all the existing counters are reset:
• L2 ingress access list
• L3 egress access list
• L2 egress access list
If a rule is simply appended, existing counters are not aected.
Table 7. L2 and L3 Filtering on Switched Packets
L2 ACL Behavior L3 ACL Behavior Decision on Targeted Trac
Deny Deny L3 ACL denies.
Deny Permit L3 ACL permits.
Permit Deny L3 ACL denies.
Permit Permit L3 ACL permits.
NOTE: If you congure an interface as a vlan-stack access port, only the L2 ACL lters the packets. The L3 ACL applied to such
a port does not aect trac. That is, existing rules for other features (such as trace-list, policy-based routing [PBR], and QoS)
are applied to the permitted trac.
For information about MAC ACLs, refer to Layer 2.
Assign an IP ACL to an Interface
To pass trac through a congured IP ACL, assign that ACL to a physical interface, a port channel interface, or a VLAN.
The IP ACL is applied to all trac entering a physical or port channel interface and the trac is either forwarded or dropped depending on
the criteria and actions specied in the ACL.
The same ACL may be applied to dierent interfaces and that changes its functionality. For example, you can take ACL “ABCD” and apply it
using the in keyword and it becomes an ingress access list. If you apply the same ACL using the out keyword, it becomes an egress
access list. If you apply the same ACL to the Loopback interface, it becomes a Loopback access list.
This section describes the following:
• Congure Ingress ACLs
• Congure Egress ACLs
For more information about Layer-3 interfaces, refer to Interfaces.
Applying an IP ACL
To apply an IP ACL (standard or extended) to a physical or port channel interface, use the following commands.
1 Enter the interface number.
CONFIGURATION mode
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Access Control Lists (ACLs)