The mere mention of that word starts an immediate flurry of word association. Things like “broadcast storm”, “loops”, and “outage” spring to mind, all the while palms get sweaty reminiscing the memories of bridge calls with angry and impatient end users. To be honest, the Spanning-tree protocol gets a bad wrap. Its whole purpose is … More Spanning-tree (STP) and ACI
One issue that can arise when we connect ACI and Legacy STP environments is intermittent packet loss to ACI endpoints due to Spanning-tree TCNs. TCNs will trigger ACI to flush endpoints in the EPG on which the TCN was received. ACI does re-learn the endpoints based on normal data-plane learning, but if the TCNs are … More STP and ACI: Intermittent packet loss due to TCNs
UPDATE – The Common Pervasive Gateway feature has been deprecated and is not actively maintained anymore. When operating more than one Cisco ACI fabric, we highly recommend that you deploy Multi-Site instead of interconnecting multiple individual ACI fabrics to each other through leaf switches using the Common Pervasive Gateway feature. The Common Pervasive Gateway feature … More ACI Common Pervasive Gateway
There are certain times when CIMC access to your APIC is absolutely critical, for example, when you are troubleshooting a problem, upgrading your APICs, or performing a factory reset. During these times, you can access your APIC via CIMC by using the KVM console, which requires Java (or HTTP with CIMC 3.0), or by enabling … More Upgrading the CIMC for your APICs
For those of us with more than one ACI Fabric, how many times have you mistakenly logged into the wrong fabric and almost made a change that was intended for a different ACI Fabric? It’s easy to do! This problem can go downhill fast when you are just trying to test something in your lab, … More Configuring an APIC Banner (GUI Alias)
Did you know that you can enable logging for permitted and denied traffic that flows through your ACI Fabric? While this feature is not meant as a replacement for Tetration or Netflow, this can be a great tool for troubleshooting and examining traffic that is flowing through applications that reside in your ACI Fabric. In … More Logging ACL/Contract Permits and Denies with ACI
ACI contains a plethora of information. Using SYSLOG to get that information from all of the devices in your fabric to a centralized SYSLOG server is still a good way of aggregating logging data, alerts, and audit information. In this post, we’ll review what data is available to be forwarded to your external SYSLOG server, … More Configuring Syslog for ACI
One of the most frequent topics that comes up when I am discussing ACI with customers, is, “How can we better operationalize ACI?”. In other words, how can we take what we have with ACI, and make it simpler to consume for not only ourselves, but for our Ops staff? Operationalizing and maintaining contracts between … More Operationalizing ACI: Contracts Viewer
Originally I was going to create a detailed configuration guide for Multi-Pod, however, after checking out the the Cisco ACI MultiPod Configuration Whitepaper on CCO I realized I would be duplicating efforts at best. The configuration whitepaper on CCO contains detailed configuration examples for the IPN and screenshots from the APIC. If you are looking … More ACI Multi-Pod Caveats and Considerations
I’d like to thank Soumitra Mukherji for his work on this post! When configuring MultiPod, a frequently asked question that often comes up is how to configure QOS between the ACI Fabric and the IPN network, to ensure that critical ACI fabric traffic is not dropped. With this article, we will go through configuration examples of … More ACI Multi-Pod QOS