Symptom

- Smart licensing fails to register with the following error message: %SMART_LIC-3-COMM_FAILED: Communications failure with the Cisco Smart Software Manager (CSSM) : No detailed information given - "show license tech support" will show that the reason for communication failure is "NO REPLY" Communication Statistics: ======================= Communication Level Allowed: INDIRECT Overall State: Trust Establishment: Attempts: Total=10, Success=0, Fail=10 Ongoing Failure: Overall=10 Communication=10 Last Response: NO REPLY on Sep 11 20:07:51 2023 UTC - packet capture or DNS debug will reveal that the affected device resolves AAAA record (IPv6), but never tries to resolve A record (IPv4)

Conditions

- Smart transport enabled - IPv6 is enabled on any interface - HTTP client source interface is not configured for IPv6 - Device is able to resolve CSSM AAAA (IPv6) DNS record

Workaround

- None

Further Problem Description