Troubleshooting Physical Constructs Methodology

Troubleshooting Physical Constructs Methodology

During fabric configuration at the switch and interface level, as a preparation to deploy the logical constructs configured from the tenant, different issues may occur. Thus, you should be able to troubleshoot the physical constructs to resolve specific issues. You should verify that they are configured as needed, often using Cisco best practices, and inspect each physical construct, such as the domains, VLAN pools, AAEP, interface policies and interface policy groups, as well as interface and switch profiles.

The following examples show a brief configuration of the physical constructs in the ACI policy, which can help you detect issues in your environment as a result of configuration errors.

When the VMM domain is created, it is connected to a hypervisor, and more specifically a vSwitch instance. Therefore, using the Virtual Network option in the top menu of the APIC GUI, you can choose Kubernetes, Microsoft, OpenStack, VMware, and so on. The following example depicts a VMware domain:

The configured domain should be associated with a VLAN pool, which you can create using the Fabric > Access Policies > Pools > VLAN. When creating VMM domains, you should use dynamic allocations, while for physical and external Layer 2/Layer 3 domains should use static.

Therefore, add dynamic VLANs or ranges of dynamic VLANs for VLANs connecting to different VMMs, such as Kubernetes, Microsoft, OpenStack, VMware, and so on. Also, add static VLANs or ranges of static VLANs for other type of domains (physical, external Layer 2/Layer 3). Some VLAN pools can be shared by multiple domains.

The AAEP is used to map domains (physical or virtual) to interface policies, with the end goal of mapping VLANs to interfaces. Thus, you should utilize AAEPs as part of the fabric access configuration. This figure shows the AAEP usage in Cisco ACI fabric:

You should be aware that an AAEP is a purely logical construct and does not represent physical resources directly. When creating the AAEP, you only assign a name using the Fabric > Access Policies > Policies > Global > Attachable Access Entity Profile menu. You can reference domains that are already created or create domains later.