摘要:
Fast flooding based fast convergence to recover from a network failure. A router detects a network failure, and responsive to that failure, transmits a fast failure notification message to a set of one or more routers. The fast failure notification message includes information that identifies the network failure and also indicates that the fast failure notification message is to be flooded by the set of routers independently of convergence. The router updates a routing table to reflect the network failure. The transmission of the fast failure notification message is performed prior to completion of the routing table update to reflect the network failure.
摘要:
A router detects a network failure and responsive to that failure, floods a fast failure notification message out a set of interfaces of the router. The fast failure notification message includes information that identifies the network failure and includes as its source MAC (Media Access Control) address a MAC address that is assigned to an interface that is coupled with the detected network failure and is not part of the set of interfaces of the router. The router updates a routing table to reflect the network failure. The flooding of the fast failure notification message is performed prior to completion of the routing table update to reflect the network failure.
摘要:
Fast flooding based fast convergence to recover from a network failure. A router detects a network failure, and responsive to that failure, transmits a fast failure notification message to a set of one or more routers. The fast failure notification message includes information that identifies the network failure and also indicates that the fast failure notification message is to be flooded by the set of routers independently of convergence. The router updates a routing table to reflect the network failure. The transmission of the fast failure notification message is performed prior to completion of the routing table update to reflect the network failure.
摘要:
A router detects a network failure and responsive to that failure, floods a fast failure notification message out a set of interfaces of the router. The fast failure notification message includes information that identifies the network failure and includes as its source MAC (Media Access Control) address a MAC address that is assigned to an interface that is coupled with the detected network failure and is not part of the set of interfaces of the router. The router updates a routing table to reflect the network failure. The flooding of the fast failure notification message is performed prior to completion of the routing table update to reflect the network failure.
摘要:
Methods and apparatus for a network element to handle LSID collisions to prevent different LSAs associated with different routes from sharing the same LSID. According to one embodiment, responsive to determining that a tentative LSID that is generated for a first route that is being added collides with an LSID that is assigned to an LSA for a second route, and that one of the first and second routes is a host route, the host route is suppressed. If the first route is the host route, suppressing includes not originating an LSA for the first route. If the second route is the host route, suppressing includes purging the LSA for the second route and not originating an LSA for the second route. Although the host route is suppressed, network reachability of the range subsuming the host route is provided through the route that is not the host route.
摘要:
A network element implementing Multiprotocol Label Switching to automatically create an optimal deterministic back-up Label Switch Path (LSP) that is maximally disjointed from a primary LSP to provide a reliable back up to the primary LSP. The network element receives a request for a generation of an LSP, determines that the request for the generation of the LSP is for the back-up LSP, locates each link of the primary LSP in a traffic engineering database, modifies each link of the primary LSP to have a link cost significantly greater than an actual link cost to discourage use of each link of the primary LSP in the back-up LSP, executes a Constrained Shortest Path First algorithm to obtain the back-up LSP, wherein the back-up LSP has a maximum disjointedness from the primary LSP due to a modified cost of each link of the primary LSP, and returns the back-up LSP.
摘要:
Methods and apparatus for a network element to handle LSID collisions to prevent different LSAs associated with different routes from sharing the same LSID. According to one embodiment, responsive to determining that a tentative LSID that is generated for a first route that is being added collides with an LSID that is assigned to an LSA for a second route, and that one of the first and second routes is a host route, the host route is suppressed. If the first route is the host route, suppressing includes not originating an LSA for the first route. If the second route is the host route, suppressing includes purging the LSA for the second route and not originating an LSA for the second route. Although the host route is suppressed, network reachability of the range subsuming the host route is provided through the route that is not the host route.
摘要:
A network element implementing Multiprotocol Label Switching to automatically create an optimal deterministic back-up Label Switch Path (LSP) that is maximally disjointed from a primary LSP to provide a reliable back up to the primary LSP. The network element receives a request for a generation of an LSP, determines that the request for the generation of the LSP is for the back-up LSP, locates each link of the primary LSP in a traffic engineering database, modifies each link of the primary LSP to have a link cost significantly greater than an actual link cost to discourage use of each link of the primary LSP in the back-up LSP, executes a Constrained Shortest Path First algorithm to obtain the back-up LSP, wherein the back-up LSP has a maximum disjointedness from the primary LSP due to a modified cost of each link of the primary LSP, and returns the back-up LSP.
摘要:
A method and apparatus for LDP-IGP synchronization for broadcast networks. In one embodiment of the invention, responsive to a network element bringing up an adjacency with a Designated Router of the broadcast network on a broadcast interface, that network element advertises in its Link State Advertisement (LSA) a peer-to-peer (P2P) adjacency to each member of the broadcast network that has bidirectional IGP communication with the network element instead of advertising a pseudo-node adjacency to the pseudo-node of the broadcast network. Each P2P adjacency includes a high cost to discourage use of those links for transit traffic. After LDP becomes operational with all neighbors on the broadcast interface, the network element advertises the pseudo-node adjacency instead of the P2P adjacencies. Accordingly, transit traffic is avoided through that network element until LDP is operational with all neighbors on the broadcast interface.
摘要:
A method and apparatus for performing a dynamically runtime adjustable constrained shortest path first (CSPF) computation of a label switched path (LSP) is described. In one embodiment of the invention, a network element acting as a source of the LSP receives a request to compute the LSP which includes one or more traffic engineering constraints. If the request includes at least one additive constraint, the network element performs a CSPF calculation. If the request does not include an additive constraint, the network element prunes each link that does not satisfy each of the constraints, and prunes those links whose paths converge at an intermediary network element according to cost, calculates a path to the destination according to cost. Other methods and apparatuses are also described.