The Embedded Logic Analyzer Module (ELAM) is a tool that assists in looking into the treatment given by the ASICs to an individual packet and how that packet is being forwarded. The tool is part of the forwarding pipeline of the ASICs and can capture packets in real time without affecting performance or control plane resources. ELAM is primarily an internal debug CLI tool for Cisco TAC. It requires knowledge of internal architecture of various types of Cisco ASIC. ELAM Assistant provides a way through the APIC GUI for users to perform the packet capture with ELAM, without any special knowledge. Starting from APIC release 6.1.2, ELAM Assistant has become a functionality that is available on APIC. Prior to 6.1.2, ELAM Assistant was available as an application of Cisco AppCenter that can be optionally installed on APIC. This document focuses on ELAM Assistant that is natively embeded in APIC from 6.1.2 or newer version.

In a Cisco Application Centric Infrastructure (ACI) fabric switch, ELAM can help determine if the packet reached the forwarding engine, what are the packet properties, was the packet dropped, is the policy applied to the packet, which policy is applied to the packet, and much more. ELAM is extremely powerful, granular, and non-intrusive.