This article describes a feature for Tap Aggregation mode, which strips IEEE 802.1BR E-Tag and Cisco VN-Tag headers from all tagged packets received on tap interface before delivering them out of tool interfaces.

DANZ provides a set of features and tools to enhance instrumentation and network/ application performance monitoring with the following key functional areas.

This feature adds support for allowing multiple destinations in a single monitor session.

This feature terminates GRE packets on a TapAgg switch by stripping the GRE header and then letting the decapped packets go through the normal TapAgg path. With this feature, we can use an L3 GRE tunnel to transit tapped traffic to the TapAgg switch over an L3 network. That would widely extend the available use cases for TapAgg.

This feature extends the capabilities of Tap Aggregation traffic steering to allow for using traffic policies.

This article describes the TAP Aggregation 802.1Q (VLAN) tag stripping feature. This feature allows up to two of the outermost incoming 802.1Q tags to be stripped, and can be configured on a traffic steering policy or a tool port.

This article describes the Tap Aggregation MAC Address Replacement feature. This feature provides the ability to configure user-specific values to replace the destination and source MAC addresses of packets forwarded by Tap Aggregation.

This article describes the Tap Aggregation MPLS Pop feature. The purpose of this feature is to support tools that do not parse MPLS labels and therefore need the switch to remove (pop) the MPLS header.

Support for independently editing packets copied to multiple tool interfaces.

A Tap Aggregation steering policy can redirect and replicate incoming traffic streams, as well as apply various packet editing actions, e.g., VLAN identity tagging, MAC address rewrite, timestamping, header removal, etc.

This feature provides support for packet counters for Tap Aggregation on default forwarding, GRE tunnel termination, traffic steering based on policy map and traffic steering based on traffic policy (Aegis). For brevity, counters for policy-map traffic steering will be referred to as policy-map counters, and counters for traffic-policy traffic steering will be referred to as traffic-policy counters.

As of EOS-4.25.2F some advanced Tap Aggregation features require the hardware forwarding profile to be set. On EOS-4.25.2F these features are MPLS Pop and 802.1br-E/VN Tag Stripping.

Tap aggregation traffic steering allows users to redirect traffic flows received on TAP interfaces based on configurable policy-map rules. This feature enables the ability to define policy-map rules that filter on IP header fields on the following Ethernet-over-MPLS packet types.

Internal recirculation interfaces, IR interfaces, can be used to internally loop-back packets for a second pass through the packet forwarding pipeline. This is particularly useful with Tap Aggregation because some combinations of advanced Tap Aggregation features cannot be simultaneously applied to a packet. Using an IR interface however, a user can apply multiple Tap Aggregation egress editing features, overcoming previous limitations.

In TAP Aggregation mode, configuration options are provided to handle special packet types. When receiving a packet whose Frame Check Sequence (FCS) is corrupted, the default behavior is to replace the bad FCS with the correct value and forward it. Configuration options are available to control the FCS behavior, such as to discard errors, pass through the bad FCS, or append a new FCS.

This feature comprises two parts:

To extend Traffic Steering to Nexthop Groups (GRE) by allowing us to specify one or more nexthop groups of type DzGRE (DANZ GRE) as the destination for a TAP aggregation steering policy. A DzGRE header will be encapsulated to the packets sending out a nexthop group of type DZGRE.

To extend GRE Tunnel Termination by allowing decapsulation of traffic received from nexthop groups of type DZGRE and adding VLAN tags based on DZGRE metadata.

Traffic steering to nexthop groups allows specifying one or more nexthop groups as the destination for a TAP aggregation steering policy. Traffic steering is a TAP aggregation process that uses class maps and policy maps to direct data streams received on TAP ports. 

This article describes the TAP Aggregation User Defined Fields feature. The purpose of the User Defined