General

Saturn (8711-32FH-M) is a Krypton-based RPLC platform with identical hardware capabilities to Falcon (8711-48Z-M) and Thor (8711-28H8F-M). All three platforms share the same card_class (rplc-sff), architecture (x86_64), and NPU capabilities (P100/K100 support). UDLD is fully implemented in the SPIO layer and datapath for all NPU modes. The missing card instance mapping is a configuration oversight that artificially restricts a supported feature from Saturn customers, creating an inconsistent user experience across equivalent platforms.

Symptom

UDLD configuration is rejected on Saturn (8711-32FH-M / P100) platform with CLI error: RP/0/RP0/CPU0:router(config-if)#ethernet udld ^ % Invalid input detected at '^' marker. The same configuration succeeds without error on Falcon (8711-48Z-M / K100) platform running identical IOS-XR software version.

Conditions

Platform: Saturn 8711-32FH-M (P100 NPU mode) IOS-XR Version: 26.1.1.15I and later Interface: Any Ethernet interface (e.g., HundredGigE, FourHundredGigE) Configuration: Attempting to enable UDLD with ethernet udld command under interface configuration mode The issue is deterministic - occurs 100% of the time on Saturn platform

Workaround

Post-Fix (After applying CSCws16304 fix): After upgrading to an IOS-XR image that includes this fix: Configure UDLD on interfaces normally: Verify UDLD configuration: UDLD should work correctly

Further Problem Description