Known Issues

As of release 1.1.1, Cisco Nexus 3550-T Programmable Switch Platform has the following known issues and limitations:

Time To Live (TTL) Processing

The forwarded IP packet carries the same TTL when leaving Nexus 3550-T.

Frame Checksum (FCS) Processing

The Nexus 3550-T operates in cut-through mode only where the forwarding decisions are made well before the FCS arrives. The frames with incorrect FCS will get forwarded with incorrect FCS. However, the CRC errors counter available from the CLI will reflect the number of corrupt frames received by Nexus 3550-T.

Runt Frame Processing

A malformed frame, such as a runt frame (an ethernet frame shorter than 64 bytes, including the FCS), can put the switch fabric into an unstable state.

Multicast Routing Lock-up

The multicast routing causes lock-up issue where the downstream ports stop forwarding L3 multicast traffic.

Nexus 3550-T as the FHR During Multicast Routing

Nexus 3550-T cannot be directly attached to the sender in a multicast routing network.

PIM Join/Prune Handling

When Nexus 3550-T acts as an intermediate router in a multicast routing network, occasionally, a PIM Join/Prune packet can be miss from the downstream router, requiring the receiving host to send an IGMP join again to the Last Hop Router. Otherwise, traffic only starts flowing after the Join/Prune timer on the downstream router elapses.

When multiple hosts are sharing the port channel in Nexus 3550-T, there is a drop in packet throughput and the CPU utilization increases.