Robert O Sisk

US Patent:

7936670, May 3, 2011

Filed:

Apr 11, 2007

Appl. No.:

11/733904

Inventors:

John Paul Cazares - Speedway IN, US
Jade W. Clifford - Indianapolis IN, US
Charles Steven Lingafelt - Durham NC, US
Robert Barry Sisk - Chapel Hill NC, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 21/20

US Classification:

370230, 370232, 370392

Abstract:

System method and program for controlling access to a VLAN via a port of a VLAN switch system. In response to receipt of a message packet at the port, the switch system determines if a MAC address of the packet matches a MAC address for which the port has been programmed to recognize as a MAC address of a device authorized to communicate with the port. The MAC address of the packet does not match a MAC address for which the port has been programmed to recognize as a MAC address of a device authorized to communicate with the port. In response, the switch system blocks the packet if a rate of ill-formed packets and/or packets from an unrecognized MAC address exceeds a threshold pass rate. The threshold pass rate can be adjusted based on the rate of change of receipt of ill-formed packets and/or packets from an unrecognized MAC address.