This is a memo and reminder about the routing limitations that I stumbled into when working with Nexus 9000 series switches running NX-OS.
| Feature | Limitation | Link to documentation |
|---|---|---|
| PBR | You cannot configure PBR on port-channel subinterfaces | Interfaces configuration guide for 9.3(x) |
| QoS | You cannot configure QoS on port-channel subinterfaces | QoS configuration guide for 9.3(x) |
| QoS | You cannot configure egress QoS on Ethernet subinterfaces | QoS configuration guide for 9.3(x) |
For example, when I wanted to police the traffic outbound to an external connection, routed on an Ethernet subinterface, I couldn’t do that. And since I had the upstream link as a layer 3 port-channel with subinterfaces, I couldn’t do the policing there (inbound) either.
At the time of this writing (21-Feb-2021) the recommended NX-OS release for Nexus 9000 series switches is 7.0(3)I7(9). It has additional limitation:
| Feature | Limitation | Link to documentation |
|---|---|---|
| Subinterfaces | There is no statistics available for subinterfaces on NX-OS 7.x (it works starting from 9.3(3) with some limitations: 9.3(x)) | Interfaces configuration guide for 7.x |
Links for Cisco Nexus 9000 series switches: