Back to results
US 7,889,712 B2Granted
Methods and apparatus for providing loop free routing tables
AssigneeCisco Technology, Inc.
InventorsDheerendra Talur, Rex Fernando, Avneesh Sachdev, Derek Man-Kit Yeung
Life of this patent
Estimating the term…
Abstract
A router is described that includes a routing table containing route information and a module to evaluate a route and detect a loop path associated with the route using the routing table. A process is described to detect and eliminate routing loops associated with recursive routes in a routing table, so as to provide a routing table that will be loop free.
Claims20
A router comprising:
- a routing module configured to maintain a routing table containing route information to determine data traffic routes;
- a module to evaluate remote next hops in response to path changes in a route of the routing table and to detect a loop path associated with the route, the module to add the loop path to a hidden list, the module further to maintain a list of remote next hops associated with paths of the route that are not hidden;
- and
- a hidden timer to periodically trigger a timer thread and to reevaluate the route associated with the loop path added to the hidden list.
1 more element
A router comprising:
- a routing module configured to maintain a routing table containing route information;
- a module to evaluate remote next hops in response to path changes in a route using the routing table and detect a loop path associated with the route, the module to maintain a list of remote next hops associated with paths of the route and to designate remote next hops resulting in a loop path as inactive;
- and
- a hidden timer to periodically trigger a timer thread and to reevaluate the paths of the route resulting in the loop path to determine whether the remote next hops should remain inactive.
1 more element
A method comprising:
- evaluating remote next hops in communication routes in a system to detect path loops in response to changes in the communication routes;
- maintaining a list of remote next hops associated with each route;
- designating routes associated with a loop as inactive routes;
- and
- periodically reevaluating the inactive routes associated with the loop and, based on a determination that the inactive routes are no longer associated with the loop, removing the designation of the inactive route and redesignating the inactive routes as active.
2 more elements
A method comprising:
- evaluating remote next hops in communication routes in a system to detect path loops in response to changes in the communication routes;
- designating routes associated with a loop as inactive routes;
- maintaining a list of remote next hops associated with each route;
- periodically re-evaluating the inactive routes to determine whether a previously detected loop has been eliminated;
- and
- based on a determination that the previously detected loop has been eliminated, re-designating routes associated with an eliminated loop as active routes.
3 more elements
A router comprising:
- means for evaluating remote next hops in communication routes in a system to detect path loops in response to changes in the communication routes;
- means for maintaining a list of remote next hops associated with each route;
- means for designating routes associated with a loop as inactive routes;
- and
- means for periodically reevaluating the inactive routes and making a determination whether the inactive routes remain associated with a loop.
2 more elements
Dependencies are inferred from the claim text.