摘要:
A technique enables an intermediate network node to efficiently process link-state packets using a single running context (i.e., process or thread). The intermediate network node floods received link-state packets (LSP) before performing shortest path first (SPF) calculations and routing information base (RIB) updates. In addition, the node limits the number of LSPs that are permitted to be flooded before the node performs its SPF calculations. More specifically, if the number of link-state packets that are flooded during a flooding cycle exceeds a first predetermined threshold value, the node performs the SPF calculations before additional packets may be flooded. The intermediate network node also limits how long its RIB update may be delayed in favor of flooding operations. When the number of LSPs flooded after the SPF calculations exceeds a second predetermined threshold value or there are no more packets to be flooded, the node updates the contents of its RIB based on the SPF calculations.
摘要:
A method and apparatus are disclosed for performing a shortest path first network routing path determination in a data communications network based in part on information about links that are associated as shared risk link groups. Micro-loops are avoided in computing shortest path first trees by considering whether links are within shared risk link groups. In a first approach, for each link state packet in a link state database, listed adjacencies are removed if the link between the node originating the LSP and the reported adjacency belongs to a shared risk link group for which one component (local link) is known as down, and a shortest path first computation is then performed. In a second approach, during the SPT computation and after having added a first node to a path, each neighboring node is added to a tentative tree if and only if, a link between the first node and the neighboring node does not belong to a shared risk link group for which one component (local link) is known as down.
摘要:
A method of identifying an egress point to a network location in a data communications network comprising a plurality of nodes and links there between comprises the step, performed at the identifying node, of receiving a notification through the network advertising an adjacency to a network location. The method further comprises the steps, performed at the identifying node, of deriving from the notification adjacency information and identifying, from the adjacency information, the egress point.
摘要:
A method and system for failure notification at a remote node in communication with a local node are disclosed. The local node is configured for faster failure detection than the remote node. In one embodiment, the method includes establishing a failure monitoring session between the local node and the remote node, receiving at the remote node, a failure notification from the local node, the failure notification sent using a protocol of the failure monitoring session, and rerouting traffic at the remote node in response to the failure notification.
摘要:
In one embodiment, a device (e.g., a path computation element, PCE) monitors a tunnel set-up failure rate within a computer network, and determines whether to adjust an accuracy of routing information based on the tunnel set-up failure rate. For instance, the tunnel set-up failure rate being above a first threshold indicates a need for greater accuracy. In response to the tunnel set-up failure rate being above the first threshold, the device may then instruct one or more routers to shorten their routing update interval in the computer network.
摘要:
A technique incorporates an efficient means for avoiding micro-loops on a backup path associated with a failed protected link. An intermediate node delays updating a forwarding database (FDB) contained in the intermediate node based on the intermediate node's distance from the failed link. Specifically, intermediate nodes near the failed protected link delay updating their FDBs for a longer period of time than nodes farther away from the failed link. By updating FDBs in this manner, micro-loops may be avoided on the failed link's backup path as nodes on the backup path that are close to the failed link do not update their FDBs ahead of nodes farther away on the backup path.
摘要:
A technique configures an intermediate network node to automatically determine whether a route advertised by a routing protocol is important for fast convergence in a computer network. As used herein, an important route needed for fast convergence is a route advertised by the routing protocol, such as an exterior gateway routing protocol (EGP) process executing on the node, as a next-hop address, since external connectivity relies on such a route. Notably, the EGP process interacts with an interior gateway routing protocol (IGP) process executing on the node to identify the route as an important route. Identification of an important route, in turn, allows IGP to process the route in a high priority fashion, thereby facilitating fast convergence.
摘要:
A technique incorporates an efficient means for avoiding micro-loops on a backup path associated with a failed protected link. An intermediate node delays updating a forwarding database (FDB) contained in the intermediate node based on the intermediate node's distance from the failed link. Specifically, intermediate nodes near the failed protected link delay updating their FDBs for a longer period of time than nodes farther away from the failed link. By updating FDBs in this manner, micro-loops may be avoided on the failed link's backup path as nodes on the backup path that are close to the failed link do not update their FDBs ahead of nodes farther away on the backup path.
摘要:
In one embodiment, a path computation element (PCE) in a computer network receives one or more path computation requests (PCReqs), and records a time of each PCReq and the corresponding requested bandwidth. Based on this information, the PCE may determine a traffic profile of the computer network, and may augment a traffic engineering database (TED) with requested bandwidth according to time based on the traffic profile. As such, prior to a particular time, the PCE may determine placement of tunnels within the traffic profile for the particular time.
摘要:
In one embodiment, once activation of use of a backup tunnel is detected for a primary tunnel, then a level of congestion of the path of the backup tunnel may be determined. In response to the level being greater than a threshold, a head-end node of the primary tunnel is triggered to reroute the primary tunnel (e.g., requesting to a path computation element). Conversely, in response to the level not being greater than the threshold, the backup tunnel is allowed to remain activated.