The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 22, 2011
Filed:
Jan. 20, 2006
Lionel Florit, Greenbrae, CA (US);
Robert W. Klessig, Los Altos Hills, CA (US);
Lionel Florit, Greenbrae, CA (US);
Robert W. Klessig, Los Altos Hills, CA (US);
Cisco Technology, Inc., San Jose, CA (US);
Abstract
Various systems and methods for preventing loops in the presence of control plane failures are disclosed. For example, one method involves sending a special data packet in response to detection of a break in a network loop and then unblocking a port if the special data packet fails to circumnavigate the network loop. Prior to detection of the break, the port was blocked by a loop prevention protocol, such as a spanning tree protocol. If the special data packet successfully circumnavigates the network loop, the port will not be unblocked.