February 18, 2013

Packet of Death interrupting Intel-NICs

As reported by Kristian Kielhofner there seems to be an issue in some Intel NICs shipped with the 82475-chip onboard. Packets with certain content causes the NIC to fail, which results in a disconnect and traffic disruption.Quite interesting, as the failure was more or less found by accident during drops of SIP-Calls. During the SDP-Sessions Kris recognized some weird Traffic (duplicate Audio Offers, some other traffic duplications) followed by a “link down”. Yes, link down. Combined with a lights out at the switch and loss of communication between the computer system and the PHY on the NIC. Short and simple: If the Packet contains a certain bitmap the EEPROM on the NIC interprets the data wrongly and shuts down the interface.

There seems to be a correllation between the ptime of the audio stream and the failure. Kris found that a ptime=20 was erroneous and caused the NIC to drop the link. Following this link you’ll find the necessary inormation for finding out if your hardware is affected by the fail. There’s no personal evidence if the controller is built in into other pieces of hardware. But if there’s a fail in the EEPROM it maybe affect other hardware too, e.g. routers of different vendors.