SNMPv3 AES Cipher bug in IOS-XR 5.3.4 (ASR9000)

Just run into a IOS-XR bug with running SNMP v3 with AES-128 cipher (as well as AES-192 and AES-256) on ASR 9000 Routers running 5.3.4 Code.

Apparently Cisco BUG ID CSCvd35831. Fixed in 6.2.xx code.

Upgrading ASR9K is fun that can take 4-5 hours per box but having SNMP communications secure is more important. Consider upgrading.