Loop avoidance during network convergence in switched networks
First Claim
1. A method comprising:
- detecting a topology change within a network in which a segment routing (SR) protocol is implemented, whereinthe topology change disrupts an existing forwarding path between a first network node and a destination network node;
calculating new forwarding table information in response to the topology change, whereinthe new forwarding table information comprises forwarding table information for at least one updated forwarding path from the first network node to the destination network node, andthe new forwarding table information is generated according to the SR protocol;
identifying a maximum time for at least a portion of the network to reach a post-convergence state with respect to the topology change;
until the maximum time has elapsed at the first network node,explicitly specifying at least a portion of the at least one updated forwarding path in a packet header of a packet, if the packet is being sent from the first network node to the destination network node; and
after the maximum time has elapsed at the first network node,non-explicitly specifying the at least the portion of the at least one updated forwarding path in a packet header of an additional packet, if the additional packet is being sent from the first network node to the destination network node, whereinthe detecting, the calculating, the identifying, the explicitly specifying, and the non-explicitly specifying are performed by the first network node.
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Accused Products
Abstract
Various techniques can be used to avoid loops during network convergence after a topology change such as a failure. For example, a method can involve detecting a failure that disrupts an existing forwarding path between a node and a destination node; calculating at least one updated forwarding path from the node to the destination node; identifying a maximum time for at least a portion of the network to reach a post-convergence state with respect to the failure; until the maximum time has elapsed at the node, explicitly specifying at least a portion of the updated forwarding path in packet headers of any packets being sent from the node to the destination node; and after the maximum time has elapsed at the node, non-explicitly specifying the portion of the updated forwarding path in packet headers of any additional packets being sent from the node to the destination node.
167 Citations
20 Claims
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1. A method comprising:
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detecting a topology change within a network in which a segment routing (SR) protocol is implemented, wherein the topology change disrupts an existing forwarding path between a first network node and a destination network node; calculating new forwarding table information in response to the topology change, wherein the new forwarding table information comprises forwarding table information for at least one updated forwarding path from the first network node to the destination network node, and the new forwarding table information is generated according to the SR protocol; identifying a maximum time for at least a portion of the network to reach a post-convergence state with respect to the topology change; until the maximum time has elapsed at the first network node, explicitly specifying at least a portion of the at least one updated forwarding path in a packet header of a packet, if the packet is being sent from the first network node to the destination network node; and after the maximum time has elapsed at the first network node, non-explicitly specifying the at least the portion of the at least one updated forwarding path in a packet header of an additional packet, if the additional packet is being sent from the first network node to the destination network node, wherein the detecting, the calculating, the identifying, the explicitly specifying, and the non-explicitly specifying are performed by the first network node. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A non-transitory computer-readable storage medium comprising program instructions executable by a first network node to:
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detect a topology change within a network in which a segment routing (SR) protocol is implemented, wherein the topology change disrupts an existing forwarding path between the first network node and a destination network node; calculate new forwarding table information in response to the topology change, wherein the new forwarding table information comprises forwarding table information for at least one updated forwarding path from the first network node to the destination network node, and the new forwarding table information is generated according to the SR protocol; identify a maximum time for at least a portion of the network to reach a post-convergence state with respect to the topology change; until the maximum time has elapsed at the first network node, explicitly specify at least a portion of the at least one updated forwarding path in a packet header of a packet, if the packet is being sent from the first network node to the destination network node; and after the maximum time has elapsed at the first network node, non-explicitly specify the at least the portion of the at least one updated forwarding path in a packet header of an additional packet, if the additional packet is being sent from the first network node to the destination network node. - View Dependent Claims (9, 10, 11, 12, 13)
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14. A system comprising:
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one or more processors; and a memory storing program instructions executable by the one or more processors to detect a topology change within a network in which a segment routing (SR) protocol is implemented, wherein the topology change disrupts an existing forwarding path between a first network node and a destination network node, calculate new forwarding table information in response to the topology change, wherein the new forwarding table information comprises forwarding table information for at least one updated forwarding path from the first network node to the destination network node, and the new forwarding table information is generated according to the SR protocol, identify a maximum time for at least a portion of the network to reach a post-convergence state with respect to the topology change, until the maximum time has elapsed at the first network node, explicitly specify at least a portion of the at least one updated forwarding path in a packet header of a packet, if the packet is being sent from the first network node to the destination network node, and after the maximum time has elapsed at the first network node, non-explicitly specify the at least the portion of the at least one updated forwarding path in a packet header of an additional packet, if the additional packet is being sent from the first network node to the destination network node. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification