Summary
IS-IS adjacency transitions to UP state but port remains in NNI-ONBOARDING auto-sense state leading to packet loss and latency. This occurs when the IS-IS adjacency is configured using auto-sense at one end of the link and manual configuration on the other.
Background
Changes in the auto-sense algorithm in release 9.1.1.0 added a flag in the LLDP Fabric Connect TLV that is used to signal the presence of auto-sense IS-IS authorization keys. The LLDP flag is sent only if the auto-sense keys are configured and is not sent if ISIS is manually configured on the port.
Impact
Packet loss and latency for traffic involving the impacted NNI link.
Products Affected
- All VSP
- All Universal Switching Platforms running Fabric Engine
Software Affected
- VOSS/Fabric Engine 9.1.1.0
- VOSS/Fabric Engine 9.1.2.0
- VOSS/Fabric Engine 9.2.0.0
- VOSS/Fabric Engine 9.2.1.0
Workaround
Enable "auto-sense" on the NNI ports on both ends of the link.
Solution
This issue is addressed in Fabric Engine/VOSS 9.2.1.1 and 9.3.0.0 releases. (once available)
Please see the full field notice here for future updates and more details.
