Deployment Guide

IPv6 ACLs, and standard and extended MAC ACLs. Congure ACL logging only on ACLs that are applied to ingress interfaces; you
cannot enable logging for ACLs that are associated with egress interfaces.
CONFIG-STD-NACL mode
seq sequence-number {deny | permit} {source [mask] | any | host ip-address} [log [interval
minutes]]
Flow-Based Monitoring Support for ACLs
Flow-based monitoring conserves bandwidth by monitoring only the specied trac instead of all trac on the interface. It is available for
Layer 2 and Layer 3 ingress trac. You can specify trac using standard or extended access-lists. This feature copies all incoming packets
on one port and forwards (mirrors) them to another port. The source port is the monitored port (MD) and the destination port is the
monitoring port (MG).
The port mirroring application maintains and performs all the monitoring operations on the chassis. ACL information is sent to the ACL
manager, which in turn noties the ACL agent to add entries in the CAM area. Duplicate entries in the ACL are not saved.
When a packet arrives at a port that is being monitored, the packet is validated against the congured ACL rules. If the packet matches an
ACL rule, the system examines the corresponding ow processor to perform the action specied for that port. If the mirroring action is set
in the ow processor entry, the destination port details, to which the mirrored information must be sent, are sent to the destination port.
When a stack unit is reset or a stack unit undergoes a failure, the ACL agent registers with the port mirroring application. The port mirroring
utility downloads the monitoring conguration to the ACL agent. The interface manager noties the port mirroring application about the
removal of an interface when an ACL entry associated with that interface to is deleted.
Behavior of Flow-Based Monitoring
Activate ow-based monitoring for a monitoring session by entering the flow-based enable command in the Monitor Session mode.
When you enable this capability, trac with particular ows that are traversing through the ingress interfaces are examined, and
appropriate ACLs can be applied in the ingress direction. By default, ow-based monitoring is not enabled.
You must specify the monitor option with the permit, deny, or seq command for ACLs that are assigned to the source or the
monitored port (MD) to enable the evaluation and replication of trac that is traversing to the destination port. Enter the keyword
monitor with the seq, permit, or deny command for the ACL rules to allow or drop IPv4, IPv6, ARP, UDP, EtherType, ICMP, and TCP
packets. The ACL rule describes the trac that you want to monitor, and the ACL in which you are creating the rule will be applied to the
monitored interface. Flow monitoring is supported for standard and extended IPv4 ACLs, standard and extended IPv6 ACLs, and standard
and extended MAC ACLs.
CONFIG-STD-NACL mode
seq sequence-number {deny | permit} {source [mask] | any | host ip-address} [count [byte]]
[monitor]
If the number of monitoring sessions increases, inter-process communication (IPC) bandwidth utilization will be high. The ACL manager
might require a large bandwidth when you assign an ACL, with many entries, to an interface.
The ACL agent module saves monitoring details in its local database and also in the CAM region to monitor packets that match the
specied criterion. The ACL agent maintains data on the source port, the destination port, and the endpoint to which the packet must be
forwarded when a match occurs with the ACL entry.
If you congure the flow-based enable command and do not apply an ACL on the source port or the monitored port, both ow-based
monitoring and port mirroring do not function. Flow-based monitoring is supported only for ingress trac and not for egress packets.
134
Access Control Lists (ACLs)