Symptom

Stuck router in boot loop with FPGA upgrade message FPGA UPGRADE Done: System going for reboot System Bootstrap, Version 15.6(10r)S, RELEASE SOFTWARE (fc1) Technical Support: http://www.cisco.com/techsupport Copyright (c) 2016 by cisco Systems, Inc. Compiled Thu 24-Mar-16 15:38 by alnguyen Boot ROM1 Last reset cause: PowerOn UEA platform with 3670016 Kbytes of main memory Warning: filesystem is not clean Located asr920-universalk9_npe.03.18.06.SP.156-2.SP6-ext.bin

Conditions

ASR920 Downgrading from Polaris version to 03.18 will get the router in a boot loop.

Workaround

Upgrade to newer Polaris version or to 3.18.7SP.

Further Problem Description