which the sequence numbers were assigned by the software. The filters were assigned sequence numbers based on the order in whichthey were configured (for example, the first filter was given the lowest sequence number). The show config command in IP ACCESSLIST mode displays the two filters with the sequence numbers 5 and 10.Example of Viewing Filter Sequence for a Specified Extended ACLDell(config-ext-nacl)#deny tcp host 123.55.34.0 anyDell(config-ext-nacl)#permit udp 154.44.123.34 0.0.255.255 host 34.6.0.0 monitor 111Dell(config-ext-nacl)#show config!ip access-list extended nimuleseq 5 deny tcp host 123.55.34.0 anyseq 10 permit udp 154.44.0.0 0.0.255.255 host 34.6.0.0 monitor 111Dell(config-ext-nacl)#To view all configured IP ACLs and the number of packets processed through the ACL, use the show ip accounting access-listcommand in EXEC Privilege mode, as shown in the first example in Configure a Standard IP ACL Filter.Configure Layer 2 and Layer 3 ACLsBoth Layer 2 and Layer 3 ACLs may be configured 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 filtered against an L2 ACL.• When Dell Networking OS switches the packets, first the L3 ACL filters them, then the L2 ACL filters them.• When Dell Networking OS switches the packets, the egress L3 ACL filters the packet.For the following features, if you enable counters on rules that have already been configured 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 listIf a rule is simply appended, existing counters are not affected.Table 6. L2 and L3 Filtering on Switched PacketsL2 ACL Behavior L3 ACL Behavior Decision on Targeted TrafficDeny Deny L3 ACL denies.Deny Permit L3 ACL permits.Permit Deny L3 ACL denies.Permit Permit L3 ACL permits.NOTE: If you configure an interface as a vlan-stack access port, only the L2 ACL filters the packets. The L3 ACL applied to sucha port does not affect traffic. That is, existing rules for other features (such as trace-list, policy-based routing [PBR], and QoS)are applied to the permitted traffic.For information about MAC ACLs, refer to Layer 2.Assign an IP ACL to an InterfaceTo pass traffic through a configured IP ACL, assign that ACL to a physical interface, a port channel interface, or a VLAN.The IP ACL is applied to all traffic entering a physical or port channel interface and the traffic is either forwarded or dropped depending onthe criteria and actions specified in the ACL.118 Access Control Lists (ACLs)
