Hi Ramesh,
To integrate a SPAN device into your ACI fabric, it’s important to carefully estimate
the traffic from all source interfaces so you don’t overwhelm the destination port.
Make sure the destination port connected to the SPAN device can physically handle the expected load.
Would this be a local SPAN or ERSPAN?
If you are using ERSPAN, keep in mind that mirrored traffic will traverse the fabric and consume uplink bandwidth as well.
Checking throughput in ACI
You have a couple of options:
- APIC GUI
Fabric → Inventory → Pod → Leaf → Interfaces → Physical Interfaces → [select interface] → Stats.
This provides both real-time rates and historical graphs.
- Leaf CLI
Leaf# show interface ethernet 1/1
(Load-Interval: 5 minutes / 300 seconds) - not ideal way to estimate your consumption since this is point in time snapshot over 5 minutes.
Estimating SPAN traffic load
Required SPAN destination bandwidth ≈
Sum of (Ingress + Egress) across all source interfaces.
Do you use any external monitoring tool in your fabric? Something that provides historical graphs and peak traffic
data, would make this much more easier and accurate.
If not, SNMP polling into tools like PRTG or Grafana and so on, works well and is straightforward to set up in ACI.
If you have Nexus Dashboard Insights (NDI), it offers interface visibility with historical trending.
I hope this helps.
