US 7,626,948 B1Granted

System and method for verifying the validity of a path in a network environment

AssigneeCisco Technology, Inc.

InventorsDavid A. Cook, James L. Ng, Alvaro E. Retana, Russell I. White

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Abstract

A method for verifying a validity of a path is provided that includes receiving an advertisement communication at a first autonomous system from a second autonomous system, the advertisement communication including a list of one or more connected autonomous systems. The method also includes identifying whether the first autonomous system claims a connection to the second autonomous system and whether the second autonomous system claims a connection to the first autonomous system such that two-way connectivity is established between the autonomous systems. In response to the establishment of the two-way connectivity, a directed graph is constructed that includes two nodes representing the first and second autonomous systems respectively. An edge may be formed that connects the two nodes.

Claims21

Dependent claims

An apparatus for verifying a validity of a path, comprising:

a network element included in a first autonomous system that:
constructs a directed graph comprising a plurality of nodes and a plurality of edges, a node representing an autonomous system, an edge representing a connection between two autonomous systems, the edges marked tentative;
receives an advertisement communication from each respective autonomous system within an internetwork, the advertisement comprising a list of all autonomous systems connected to the respective autonomous system;
for each advertisement received:
determines from the respective received advertisement whether the respective autonomous system claims a connection to any of the other autonomous systems within the internetwork;
determines from any other received advertisements whether any of the other autonomous systems within the internetwork claim a connection to the respective autonomous system;
for each connection claimed by the respective autonomous system with another autonomous system within the internetwork that is reciprocated by the other autonomous system, establishes that there is two-way connectivity between the two autonomous systems;
if there is two-way connectivity between the two autonomous systems, marks the edge representing the connection between the two autonomous systems as verified in the directed graph;
and
if there is no two-way connectivity between the two autonomous systems, removes the edge representing the connection between the two autonomous systems from the directed graph.

7 more elements

A method for verifying a validity of a path, comprising:

constructing a directed graph comprising a plurality of nodes and a plurality of edges, a node representing an autonomous system, an edge representing a connection between two autonomous systems, the edges marked tentative;
receiving an advertisement communication at a first autonomous system from each respective autonomous system within an internetwork, the advertisement comprising a list of all autonomous systems connected to the respective autonomous system;
for each advertisement received:
determining from the respective received advertisement communication whether the first autonomous system claims a connection to the respective autonomous system;
determining from the advertisement communication whether the respective autonomous system claims a connection to any of the other autonomous systems within the internetwork, including the first autonomous system;
for each connection claimed by the respective autonomous system with another autonomous systems within the internetwork that is reciprocated by the other autonomous system, establishing that there is two-way connectivity between the two autonomous systems;
if there is two-way connectivity between the two autonomous systems, marking the edge representing the connection between the two autonomous systems as verified;
and
if there is no two-way connectivity between the two autonomous systems, removing the edge representing the connection between the two autonomous systems from the directed graph.

6 more elements

A system for verifying a validity of a path, comprising:

means for constructing a directed graph comprising a plurality of nodes and a plurality of edges, a node representing an autonomous system, an edge representing a connection between two autonomous systems, the edges marked tentative;
means for receiving an advertisement communication at a first autonomous system from each respective autonomous system within an internetwork, the advertisement comprising a list of all autonomous systems connected to the respective autonomous system;
for each advertisement received:
means for determining from the respective received advertisement communication whether the first autonomous system claims a connection to the respective autonomous system;
means for determining from the advertisement communication whether the respective autonomous system claims a connection to any of the other autonomous systems within the internetwork, including the first autonomous system;
means for, for each connection claimed by the respective autonomous system with another autonomous systems within the internetwork that is reciprocated by the other autonomous system, establishing that there is two-way connectivity between the two autonomous systems;
means for, if there is two-way connectivity between the two autonomous systems, marking the edge representing the connection between the two autonomous systems as verified;
and
means for, if there is no two-way connectivity between the two autonomous systems, removing the edge representing the connection between the two autonomous systems from the directed graph.

6 more elements

Software embodied in a computer readable medium, the software comprising computer code such that when executed is operable to:

construct a directed graph comprising a plurality of nodes and a plurality of edges, a node representing an autonomous system, an edge representing a connection between two autonomous systems, the edges marked tentative;
receive an advertisement communication at a first autonomous system from each respective autonomous system within an internetwork, the advertisement comprising a list of all autonomous systems connected to the respective autonomous system;
for each advertisement received:
determine from the respective received advertisement communication whether the first autonomous system claims a connection to the respective autonomous system;
determine from the advertisement communication whether the respective autonomous system claims a connection to any of the other autonomous systems within the internetwork, including the first autonomous system;
for each connection claimed by the respective autonomous system with another autonomous systems within the internetwork that is reciprocated by the other autonomous system, establish that there is two-way connectivity between the two autonomous systems;
if there is two-way connectivity between the two autonomous systems, mark the edge representing the connection between the two autonomous systems as verified;
and
if there is no two-way connectivity between the two autonomous systems, remove the edge representing the connection between the two autonomous systems from the directed graph.

6 more elements

Dependencies are inferred from the claim text.