Symptom
When ASR1k receives echo-request destined for Virtual-Access Link Local address, debug message says the router send back echo-request, but does not output the packet on the wire.
Condition
-ASR1k is used as LNS.
-The issue can be shown on 3.4.1S, but not 3.2.0S.
-Using L2TP on IPv6 environment.
