TippingPoint IPS running the TippingPoint Operating System (TOS) before 2.2.4.6519 allows remote attackers to "force the device into layer 2 fallback (L2FB)", causing a denial of service (page fault), via a malformed packet.
https://exchange.xforce.ibmcloud.com/vulnerabilities/27934
http://www.vupen.com/english/advisories/2006/2956
http://www.securityfocus.com/bid/19125
http://www.securityfocus.com/archive/1/440944/100/0/threaded
http://www.3com.com/securityalert/alerts/3COM-06-003.html
http://securitytracker.com/id?1016562