The IKEv2 implementation in Cisco IOS 15.0 through 15.6 and IOS XE 3.3 through 3.17 allows remote attackers to cause a denial of service (device reload) via fragmented packets, aka Bug ID CSCux38417.
http://www.securitytracker.com/id/1035382
http://www.securityfocus.com/bid/85311
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160323-ios-ikev2